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 136:1The theme is the same as that of Psalm 135. God should be praised for His works of creation and providence, His deliverance and care of His people, and judgments on their enemies, and His goodness to all. The chorus to every verse is in terms of that of Psa 106:1; Psa 118:1-4, and was perhaps used as the Amen by the people, in worship (compare Ch1 16:36; Psa 105:45). (Psa. 136:1-26)
The divine titles denote supremacy.
psa 136:4alone--excluding all help.
psa 136:5by wisdom--or, "in wisdom" (Psa 104:24).
made--literally, "maker of."
above the waters--or, "higher than the waters" (Psa 24:2).
psa 136:12Compare similar expressions (Exo 3:20; Deu 4:34, &c.).
psa 136:15overthrew--literally, "shook off," as in Exo 14:27, as a contemptuous rejection of a reptile.
psa 136:23remembered us--or, "for us" (Psa 132:1).
our low estate--that is, captivity.
psa 136:24And hath redeemed us--or, literally, "snatched us"--alluding to the sudden deliverance effected by the overthrow of Babylon.
psa 136:25To the special favors to His people is added the record of God's goodness to all His creatures (compare Mat 6:30).
psa 136:26God of heaven--occurs but once (Jon 1:9) before the captivity. It is used by the later writers as specially distinguishing God from idols.