3:19-21 The absolute necessity of repentance is to be solemnly charged upon the consciences of all who desire that their sins may be blotted out, and that they may share in the refreshment which nothing but a sense of Christ's pardoning love can afford. Blessed are those who have felt this. It was not needful for the Holy Spirit to make known the times and seasons of these dispensations. These subjects are still left obscure. But when sinners are convinced of their sins, they will cry to the Lord for pardon; and to the penitent, converted, and believing, times of refreshment will come from the presence of the Lord. In a state of trial and probation, the glorified Redeemer will be out of sight, because we must live by faith in him.
21. until the times—embracing the whole period between the ascension and the second advent of Christ.
restitution of all things—comprehending, probably, the rectification of all the disorders of the fall.