Jamieson, Fausset and Brown on Acts 3:22-26

22-26. a prophet ... like unto me--particularly in intimacy of communication with God (Nu 12:6-8), and as the mediatorial Head of a new order of things (He 3:2-6). Peter takes it for granted that, in the light of all he had just said, it would be seen at once that One only had any claim to be that Prophet.

him shall ye hear in all things, &c.--This part of the prediction is emphatically added, in order to shut up the audience to the obedience of faith, on pain of being finally "cut off" from the congregation of the righteous (Psa 1:1).