These things I command you,.... The doctrines which Christ spake, as one having authority, concerning the vine and branches; his love to his disciples, in laying down his life for them, and in accounting and using them as friends, and not servants; in choosing, ordaining, and sending them forth, for the ends above mentioned; these were delivered by him with this view, to promote brotherly love among them: that ye love one another; this lay much upon his heart, he often mentions it; this is the third time it is expressed by him, in these his last discourses; and indeed, since he had declared such strong love and affection for them, it was but right and proper they should love one another; nor does anything more tend to increase mutual love among the saints, than the consideration of their common interest in the unchangeable love of their Lord.

That (ἵνα)

All my teachings are to the end that you should love one another.

These things I command you, that ye love one another.

17-21. The substance of these important verses has occurred more than once before. (See on [1860]Mt 10:34-36; Lu 12:49-53, &c.).

15:9-17 Those whom God loves as a Father, may despise the hatred of all the world. As the Father loved Christ, who was most worthy, so he loved his disciples, who were unworthy. All that love the Saviour should continue in their love to him, and take all occasions to show it. The joy of the hypocrite is but for a moment, but the joy of those who abide in Christ's love is a continual feast. They are to show their love to him by keeping his commandments. If the same power that first shed abroad the love of Christ's in our hearts, did not keep us in that love, we should not long abide in it. Christ's love to us should direct us to love each other. He speaks as about to give many things in charge, yet names this only; it includes many duties.