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
psa 34:1On the title compare Sa1 21:13. Abimelech was the general name of the sovereign (Gen 20:2). After celebrating God's gracious dealings with him, the Psalmist exhorts others to make trial of His providential care, instructing them how to secure it. He then contrasts God's care of His people and His punitive providence towards the wicked. (Psa. 34:1-22)
Even in distress, which excites supplication, there is always matter for praising and thanking God (compare Eph 5:20; Phi 4:6).
psa 34:2make her boast--"glory" (Psa 105:3; compare Gal 6:14).
humble--"the pious," as in Psa 9:12; Psa 25:9.
psa 34:3magnify the Lord--ascribe greatness to Him, an act of praise.
together--"alike" (Psa 33:15), or, equally, without exception.
psa 34:4delivered . . . fears--as well as actual evil (Psa 64:1).
psa 34:5God's favor to the pious generally, and to himself specially, is celebrated.
looked--with desire for help.
lightened--or, "brightened," expressing joy, opposed to the downcast features of those who are ashamed or disappointed (Psa 25:2-3).
psa 34:6This poor man--literally, "humble," himself as a specimen of such.
psa 34:7angel--of the covenant (Isa 63:9), of whom as a leader of God's host (Jos 5:14; Kg1 22:19), the phrase--
encampeth, &c.--is appropriate; or, "angel" used collectively for angels (Heb 1:14).
psa 34:8taste and see--try and experience.
psa 34:9that fear him--who are pious--fear and love (Pro 1:7; Pro 9:10).
saints--consecrated to His service (Isa 40:31).
psa 34:10not want any good--"good" is emphatic; they may be afflicted (compare Psa 34:10); but this may be a good (Co2 4:17-18; Heb 12:10-11).
psa 34:11children--subjects of instruction (Pro 1:8, Pro 1:10).
psa 34:12What man--Whoever desires the blessings of piety, let him attend.
psa 34:13Sins of thought included in those of speech (Luk 6:45), avoiding evil and doing good in our relations to men are based on a right relation to God.
psa 34:15eyes of the Lord are upon-- (Psa 32:8; Psa 33:18).
psa 34:16face . . . against--opposed to them (Lev 17:10; Lev 20:3).
cut off the remembrance--utterly destroy (Psa 109:13).
psa 34:17Humble penitents are objects of God's special tender regard (Psa 51:19; Isa 57:15).
psa 34:20bones--framework of the body.
psa 34:21Contrast in the destiny of righteous and wicked; the former shall be delivered and never come into condemnation (Joh 5:24; Rom 8:1); the latter are left under condemnation and desolate.