All things whatsoever I have commanded you. — The words obviously point, in the first instance, to the teaching of our Lord recorded in the Gospels — the new laws of life, exceeding broad and deep, of the Sermon on the Mount, the new commandment of Love for the inner life (John 13:34), the new outward ordinances of Baptism and the Supper of the Lord. But we may well believe that they went further than this, and that the words may cover much unrecorded teaching which they had heard in the darkness, and were to reproduce in light (Matthew 10:27).
I am with you alway. — Literally, all the days, or, at all times; the words emphasising continuity more than the English adverb. The “days” that were coming might seem long and dark and dreary, but He, their Lord, would be with them, in each of those days, even to the far-off end.
Even unto the end of the world. — Literally, of the age. The phrase is the same as that in Matthew 13:39-40; Matthew 13:49; Matthew 24:13. In Hebrews 9:26 it is used of the time of the appearance of Christ in the flesh, as the beginning of the last age of the world. Like all such words, its meaning widens or contracts according to our point of view. Here the context determines its significance as stretching forward to the end of the age, or aeon, which began with the first Advent of the Christ and shall last until the second.
We ask, as we close the Gospel, why it ends thus? why there should be no record of a fact so momentous as the Ascension? The question is one which we cannot fully answer. There is an obvious abruptness in the close of the book as a book. It may be that it was left unfinished. It may be that the fact of the Ascension entered into the elementary instruction of every catechumen, and was therefore taken for granted; or that it was thought of as implied in the promise of Christ’s perpetual presence; or, lastly, that that promise seemed, in its grandeur and its blessedness, to be the consummation of all that Christ had come to accomplish, and therefore as the fitting close of the record of His life and work.