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 147:1This and the remaining Psalms have been represented as specially designed to celebrate the rebuilding of Jerusalem (compare Neh 6:16; Neh 12:27). They all open and close with the stirring call for praise. This one specially declares God's providential care towards all creatures, and particularly His people. (Psa. 147:1-20)
(Compare Psa 92:1; Psa 135:3).
psa 147:2(Compare Psa 107:3; Isa 11:12).
psa 147:3Though applicable to the captive Israelites, this is a general and precious truth.
psa 147:4God's power in nature (Isa 40:26-28, and often) is presented as a pledge of His power to help His people.
telleth . . . stars--what no man can do (Gen 15:5).
psa 147:6That power is put forth for the good of the meek and suffering pious, and confusion of the wicked (Psa 146:8-9).
psa 147:7His providence supplies bountifully the wild animals in their mountain homes.
Sing . . . Lord--literally, "Answer the Lord," that is, in grateful praise to His goodness, thus declared in His acts.
psa 147:10The advantages afforded, as in war by the strength of the horse or the agility of man, do not incline God to favor any; but those who fear and, of course, trust Him, will obtain His approbation and aid.
psa 147:13strengthened . . . gates--or, means of defense against invaders,
psa 147:14maketh . . . borders--or, territories (Gen 23:17; Isa 54:12).
filleth thee, &c.--(Compare Margin).
psa 147:15God's Word, as a swift messenger, executes His purpose, for with Him to command is to perform (Gen 1:3; Psa 33:9), and He brings about the wonders of providence as easily as men cast crumbs.
psa 147:17morsels--used as to food (Gen 18:5), perhaps here denotes hail.
psa 147:19This mighty ruler and benefactor of heaven and earth is such especially to His chosen people, to whom alone (Deu 4:32-34) He has made known His will, while others have been left in darkness. Therefore unite in the great hallelujah.