A Commentary, Critical, Practical, and Explanatory on the Old and New Testaments, by Robert Jamieson, A.R. Fausset and David Brown  at sacred-texts.com
lev 19:2A REPETITION OF SUNDRY LAWS. (Lev. 19:1-37)
Speak unto all the congregation of the children of Israel--Many of the laws enumerated in this chapter had been previously announced. As they were, however, of a general application, not suited to particular classes, but to the nation at large, so Moses seems, according to divine instructions, to have rehearsed them, perhaps on different occasions and to successive divisions of the people, till "all the congregation of the children of Israel" were taught to know them. The will of God in the Old as well as the New Testament Church was not locked up in the repositories of an unknown tongue, but communicated plainly and openly to the people.
Ye shall be holy: for I . . . am holy--Separated from the world, the people of God were required to be holy, for His character, His laws, and service were holy. (See Pe1 1:15).
lev 19:3Ye shall fear every man his mother, and his father, and keep my sabbaths--The duty of obedience to parents is placed in connection with the proper observance of the Sabbaths, both of them lying at the foundation of practical religion.
lev 19:5if ye offer a sacrifice of peace offerings unto the Lord, ye shall offer it at your own will--Those which included thank offerings, or offerings made for vows, were always freewill offerings. Except the portions which, being waved and heaved, became the property of the priests (see Lev. 3:1-17), the rest of the victim was eaten by the offerer and his friend, under the following regulations, however, that, if thank offerings, they were to be eaten on the day of their presentation; and if a freewill offering, although it might be eaten on the second day, yet if any remained of it till the third day, it was to be burnt, or deep criminality was incurred by the person who then ventured to partake of it. The reason of this strict prohibition seems to have been to prevent any mysterious virtue being superstitiously attached to meat offered on the altar.
lev 19:9And when ye reap the harvest of your land, thou shalt not wholly reap the corners of thy field--The right of the poor in Israel to glean after reapers, as well as to the unreaped corners of the field, was secured by a positive statute; and this, in addition to other enactments connected with the ceremonial law, formed a beneficial provision for their support. At the same time, proprietors were not obliged to admit them into the field until the grain had been carried off the field; and they seem also to have been left at liberty to choose the poor whom they deemed the most deserving or needful (Rut 2:2, Rut 2:8). This was the earliest law for the benefit of the poor that we read of in the code of any people; and it combined in admirable union the obligation of a public duty with the exercise of private and voluntary benevolence at a time when the hearts of the rich would be strongly inclined to liberality.
lev 19:11Ye shall not steal--A variety of social duties are inculcated in this passage, chiefly in reference to common and little-thought-of vices to which mankind are exceedingly prone; such as committing petty frauds, or not scrupling to violate truth in transactions of business, ridiculing bodily infirmities, or circulating stories to the prejudice of others. In opposition to these bad habits, a spirit of humanity and brotherly kindness is strongly enforced.
lev 19:17thou shalt in any wise rebuke thy neighbour--Instead of cherishing latent feelings of malice or meditating purposes of revenge against a person who has committed an insult or injury against them, God's people were taught to remonstrate with the offender and endeavor, by calm and kindly reason, to bring him to a sense of his fault.
not suffer sin upon him--literally, "that ye may not participate in his sin."
lev 19:18thou shalt love thy neighbour as thyself--The word "neighbour" is used as synonymous with "fellow creature." The Israelites in a later age restricted its meaning as applicable only to their own countrymen. This narrow interpretation was refuted by our Lord in a beautiful parable (Luk 10:30-37).
lev 19:19Thou shalt not let thy cattle gender with a diverse kind--This prohibition was probably intended to discourage a practice which seemed to infringe upon the economy which God has established in the animal kingdom.
thou shalt not sow thy field with mingled seed--This also was directed against an idolatrous practice, namely, that of the ancient Zabians, or fire-worshippers, who sowed different seeds, accompanying the act with magical rites and invocations; and commentators have generally thought the design of this and the preceding law was to put an end to the unnatural lusts and foolish superstitions which were prevalent among the heathen. But the reason of the prohibition was probably deeper: for those who have studied the diseases of land and vegetables tell us, that the practice of mingling seeds is injurious both to flowers and to grains. "If the various genera of the natural order GramineÃ&brvbr;, which includes the grains and the grasses, should be sown in the same field, and flower at the same time, so that the pollen of the two flowers mix, a spurious seed will be the consequence, called by the farmers chess. It is always inferior and unlike either of the two grains that produced it, in size, flavor, and nutritious principles. Independently of contributing to disease the soil, they never fail to produce the same in animals and men that feed on them" [WHITLAW].
neither shall a garment mingled of linen and woollen come upon thee--Although this precept, like the other two with which it is associated, was in all probability designed to root out some superstition, it seems to have had a further meaning. The law, it is to be observed, did not prohibit the Israelites wearing many different kinds of cloths together, but only the two specified; and the observations and researches of modern science have proved that "wool, when combined with linen, increases its power of passing off the electricity from the body. In hot climates, it brings on malignant fevers and exhausts the strength; and when passing off from the body, it meets with the heated air, inflames and excoriates like a blister" [WHITLAW]. (See Eze 44:17-18).
lev 19:23ye shall count the fruit thereof as uncircumcised; three years . . . it shall not be eaten of--"The wisdom of this law is very striking. Every gardener will teach us not to let fruit trees bear in their earliest years, but to pluck off the blossoms: and for this reason, that they will thus thrive the better, and bear more abundantly afterwards. The very expression, 'to regard them as uncircumcised,' suggests the propriety of pinching them off; I do not say cutting them off, because it is generally the hand, and not a knife, that is employed in this operation" [MICHAELIS].
lev 19:26shall not eat any thing with the blood--(See on Lev 17:10).
neither . . . use enchantment, nor observe times--The former refers to divination by serpents--one of the earliest forms of enchantment, and the other means the observation, literally, of clouds, as a study of the appearance and motion of clouds was a common way of foretelling good or bad fortune. Such absurd but deep-rooted superstitions often put a stop to the prosecution of serious and important transactions, but they were forbidden especially as implying a want of faith in the being, or of reliance on the providence of God.
lev 19:27Ye shall not round the corners of your heads, &c.--It seems probable that this fashion had been learned by the Israelites in Egypt, for the ancient Egyptians had their dark locks cropped short or shaved with great nicety, so that what remained on the crown appeared in the form of a circle surrounding the head, while the beard was dressed into a square form. This kind of coiffure had a highly idolatrous meaning; and it was adopted, with some slight variations, by almost all idolaters in ancient times. (Jer 9:25-26; Jer 25:23, where "in the utmost corners" means having the corners of their hair cut.) Frequently a lock or tuft of hair was left on the hinder part of the head, the rest being cut round in the form of a ring, as the Turks, Chinese, and Hindus do at the present day.
neither shalt thou mar, &c.--The Egyptians used to cut or shave off their whiskers, as may be seen in the coffins of mummies, and the representations of divinities on the monuments. But the Hebrews, in order to separate them from the neighboring nations, or perhaps to put a stop to some existing superstition, were forbidden to imitate this practice. It may appear surprising that Moses should condescend to such minutiÃ&brvbr; as that of regulating the fashion of the hair and the beard--matters which do not usually occupy the attention of a legislator--and which appear widely remote from the province either of government or of a religion. A strong presumption, therefore, arises that he had in mind by these regulations to combat some superstitious practices of the Egyptians.
lev 19:28Ye shall not make any cuttings in your flesh for the dead--The practice of making deep gashes on the face and arms and legs, in time of bereavement, was universal among the heathen, and it was deemed a becoming mark of respect for the dead, as well as a sort of propitiatory offering to the deities who presided over death and the grave. The Jews learned this custom in Egypt, and though weaned from it, relapsed in a later and degenerate age into this old superstition (Isa 15:2; Jer 16:6; Jer 41:5).
nor print any marks upon you--by tattooing, imprinting figures of flowers, leaves, stars, and other fanciful devices on various parts of their person. The impression was made sometimes by means of a hot iron, sometimes by ink or paint, as is done by the Arab females of the present day and the different castes of the Hindus. It is probable that a strong propensity to adopt such marks in honor of some idol gave occasion to the prohibition in this verse; and they were wisely forbidden, for they were signs of apostasy; and, when once made, they were insuperable obstacles to a return. (See allusions to the practice, Isa 44:5; Rev 13:17; Rev 14:1).
lev 19:30Ye shall keep my sabbaths, and reverence my sanctuary--This precept is frequently repeated along with the prohibition of idolatrous practices, and here it stands closely connected with the superstitions forbidden in the previous verses.
lev 19:31Regard not them that have familiar spirits--The Hebrew word, rendered "familiar spirit," signifies the belly, and sometimes a leathern bottle, from its similarity to the belly. It was applied in the sense of this passage to ventriloquists, who pretended to have communication with the invisible world. The Hebrews were strictly forbidden to consult them as the vain but high pretensions of those impostors were derogatory to the honor of God and subversive of their covenant relations with Him as His people.
neither seek after wizards--fortunetellers, who pretended, as the Hebrew word indicates, to prognosticate by palmistry (or an inspection of the lines of the hand) the future fate of those who applied to them.
lev 19:33if a stranger sojourn with thee in your land, ye shall not vex him--The Israelites were to hold out encouragement to strangers to settle among them, that they might be brought to the knowledge and worship of the true God; and with this in view, they were enjoined to treat them not as aliens, but as friends, on the ground that they themselves, who were strangers in Egypt, were at first kindly and hospitably received in that country.
lev 19:37I am the Lord--This solemn admonition, by which these various precepts are repeatedly sanctioned, is equivalent to "I, your Creator--your Deliverer from bondage, and your Sovereign, who have wisdom to establish laws, have power also to punish the violation of them." It was well fitted to impress the minds of the Israelites with a sense of their duty and God's claims to obedience.