The Lord is my strength and song. — Heb., My strength and song is Jah. The contracted form of Jehovah, Jah, is here used for the first time; but its existence in the current speech has already been indicated by the name Moriah, which occurs in Genesis 22:1. It is here used on account of the rhythm.
He is become my salvation. — Heb,, he has been to me for salvation: i.e., “he has saved me out of the hand of Pharaoh.” The beauty and force of the passage causes Isaiah to adopt it into one of his most glorious poems, the “joyful thanksgiving of the faithful for the mercies of God,” contained in his twelfth chapter. (See Exodus 15:2.)
I will prepare him an habitation. — So Onkelos and Aben-Ezra; but Jarchi, the Targums of Jerusalem and Jonathan, the LXX., and Vulg., with most moderns, translate, “I will glorify him.” It is a strong objection to the rendering of the Authorised Version that Moses is not likely to have had the idea of preparing God a habitation until the revelation of God’s will on the subject was made to him on Sinai (Exodus 25-27). The law of parallelism also requires such a meaning as “glorify” to correspond with the “exalt” of the next clause.
My father’s God. — “Father” here, by a common Hebrew idiom, stands for “forefathers” generally. (Comp. Note on Exodus 3:6.)