So will not we go back from thee; i.e. "we shall not go hack from thee any more." Gratitude for our deliverance will hind us fast to thy service. Quicken us (comp. Hosea 6:2). The prayer is for national rather than spiritual life—for a recovery from the destruction which has almost come upon them (Psalms 80:16).
And we will call upon thy Name; i.e. we will be faithful to thee henceforth; we will not go after other gods, but "call upon" thee, and thee only. The poet makes himself the spokesman of the whole nation.