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

Jamieson-Fausset-Brown Bible Commentary

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.).

Matthew Henry's Concise Commentary

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.