With the past in mind they are to maintain their former constancy, knowing that it will not be in vain. Their great need, as the whole epistle is meant to teach them, is the power of endurance, enabling them to wait on for the fulfilment of the promise given them by God (Hebrews 10:35 f.). And the time of waiting will not be long. The day foretold in Scripture (Habakkuk 2:3 f.) is close at hand, when the Coming One will appear, and those who have been faithful will enter into life, while those who have fallen back will be condemned. Our part as Christians is to be men of faith, and so to win for ourselves the coming salvation.
Hebrews 10:37. he that cometh: in this OT phrase the writer sees a reference to the Messianic title he that should come (cf. Matthew 11:3).