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 44:1In a time of great national distress, probably in David's reign, the Psalmist recounts God's gracious dealings in former times, and the confidence they had learned to repose in Him. After a vivid picture of their calamities, he humbly expostulates against God's apparent forgetfulness, reminding Him of their faithfulness and mourning their heavy sorrows. (Psa. 44:1-26)
This period is that of the settlement of Canaan (Jos 24:12; Jdg 6:3).
have told--or, "related" (compare Exo 10:2).
psa 44:2plantedst them--that is, "our fathers," who are also, from the parallel construction of the last clause, to be regarded as the object of "cast them out," which means--literally, "send" them out, or, "extend them." Heathen and people denote the nations who were driven out to make room for the Israelites.
psa 44:4Thou art my King--literally, "he who is my King," sustaining the same covenant relation as to the "fathers."
psa 44:5The figure drawn from the habits of the ox.
psa 44:6God is not only our sole help, but only worthy of praise.
psa 44:7put . . . to shame--(compare Psa 6:10), disgraced.
psa 44:8thy name--as in Psa 5:11.
psa 44:9But--contrasting, cast off as abhorrent (Psa 43:2).
goest not forth--literally, "will not go" (Sa2 5:23). In several consecutive verses the leading verb is future, and the following one past (in Hebrew), thus denoting the causes and effects. Thus (Psa 44:10-12), when defeated, spoiling follows; when delivered as sheep, dispersion follows, &c.
psa 44:11The Babylonian captivity not necessarily meant. There were others (compare Kg1 8:46).
psa 44:13(Compare Deu 28:37; Psa 79:4).
psa 44:15shame of . . . face--blushes in disgrace.
psa 44:16Its cause, the taunts and presence of malignant enemies (Psa 8:2).
psa 44:17They had not apostatized totally--were still God's people.
psa 44:18declined--turned aside from God's law.
psa 44:19sore broken--crushed.
place of dragons--desolate, barren, rocky wilderness (Psa 63:10; Isa 13:22),
shadow of death--(Compare Psa 23:4).
psa 44:20A solemn appeal to God to witness their constancy.
stretched out . . . hands--gesture of worship (Exo 9:29; Psa 88:9).
psa 44:22Their protracted sufferings as God's people attests the constancy. Paul (Rom 8:36) uses this to describe Christian steadfastness in persecution.
psa 44:23This style of addressing God, as indifferent, is frequent (Psa 3:7; Psa 9:19; Psa 13:1, &c.). However low their condition, God is appealed to, on the ground, and for the honor, of His mercy.