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
pro 27:1(Pro. 27:1-27)
Do not confide implicitly in your plans (Pro 16:9; Pro 19:21; Jam 4:13-15).
pro 27:2Avoid self-praise.
pro 27:3heavy--The literal sense of "heavy," applied to material subjects, illustrates its figurative, "grievous," applied to moral.
a fool's wrath--is unreasonable and excessive.
pro 27:4envy--or, "jealousy" (compare Margin; Pro 6:34), is more unappeasable than the simpler bad passions.
pro 27:5secret love--not manifested in acts is useless; and even, if its exhibition by rebukes wounds us, such love is preferable to the frequent (compare Margin), and hence deceitful, kisses of an enemy.
pro 27:7The luxury of wealth confers less happiness than the healthy appetite of labor.
pro 27:8Such are not only out of place, but out of duty and in danger.
pro 27:9rejoice the heart--the organ of perceiving what pleases the senses.
sweetness . . . counsel--or, "wise counsel is also pleasing."
pro 27:10Adhere to tried friends. The ties of blood may be less reliable than those of genuine friendship.
pro 27:11The wisdom of children both reflects credit on parents and contributes to their aid in difficulties.
pro 27:12(Compare Pro 20:16; Pro 22:3).
pro 27:14Excessive zeal in praising raises suspicions of selfishness.
pro 27:15(Compare Pro 19:13).
very . . . day--literally, "a day of showers."
pro 27:16hideth--or, "restrains" (that is, tries to do it); is as fruitless an effort, as that of holding the wind.
the ointment of his right hand--the organ of power (Psa 17:7; Psa 18:35). His right hand endeavors to repress perfume, but vainly. Some prefer: "His right hand comes on oil," that is, "cannot take hold." Such a woman cannot be tamed.
pro 27:17a man sharpeneth . . . friend--that is, conversation promotes intelligence, which the face exhibits.
pro 27:18Diligence secures a reward, even for the humble servant.
pro 27:19We may see our characters in the developed tempers of others.
pro 27:20Men's cupidity is as insatiable as the grave.
pro 27:21Praise tests character.
a man to his praise--according to his praise, as he bears it. Thus vain men seek it, weak men are inflated by it, wise men disregard it, &c.
pro 27:22The obstinate wickedness of such is incurable by the heaviest inflictions.
pro 27:23flocks--constituted the staple of wealth. It is only by care and diligence that the most solid possessions can be perpetuated (Pro 23:5).
pro 27:25The fact that providential arrangements furnish the means of competence to those who properly use them is another motive to diligence (compare Psa 65:9-13).
The hay appeareth--literally, "Grass appeareth" (Job 40:15; Psa 104:14).
pro 27:27household--literally, "house," the family (Act 16:15; Co1 1:16).