John 13:34

“A new commandment I give unto you, etc.] As parents, when they take their leave of their children, in their dying moments, give them proper instructions and orders, and lay their dying injunctions on them, so Christ taking his leave of his disciples, gives them his; which were, that they love one another: as brethren in the same family, children of the same Father, and fellow disciples with each other; by keeping and agreeing together, praying one for another, bearing one another’s burdens, forbearing and forgiving one another, admonishing each other, and building up one another in faith and holiness: and this he calls “a new commandment”; that is, a very excellent one; as a “new name”, and…”

“a new commandment I give unto you, That ye love one another; as I have loved you, that ye also love one another--This was the new feature of it. Christ's love to His people in giving His life a ransom for them was altogether new, and consequently as a Model and Standard for theirs to one another. It is not, however, something transcending the great moral law, which is "the old commandment" (Jo1 2:7, and see on Mar 12:28-33), but that law in a new and peculiar form. Hence it is said to be both new and old (Jo1 2:7-8).”

“A new commandment - This command he gave them as he was about to leave them, to be a badge of discipleship, by which they might be known as his friends and followers, and by which they might be distinguished from all others. It is called new, not because there was no command before which required people to love their fellow-man, for one great precept of the law was that they should love their neighbor as themselves Leviticus 19:18; but it was new because it had never before been made that by which any class or body of people had been known and distinguished. The Jew was known by his external rites, by his uniqueness of dress, etc.; the philosopher by some other mark of distinction; the…”

“A new commandment - Not new in itself; but new in the school of Christ: for he had never before taught it them expressly. Likewise new, as to the degree of it, as I have loved you. John 13:36”

“13:34-35 That the disciples were to love one another was not a new commandment (see Lev 19:18). However, that they were to love each other with the sort of love modeled by Jesus was dramatic. Jesus’ love for God was expressed in perfect obedience (John 14:31); now this kind of love was his command—that disciples express their love for Jesus in committed obedience.”

“A new: Gal 6:2; Jo1 2:8-10, Jo1 3:14-18, Jo1 3:23; Jo2 1:5 That ye love: Joh 15:12, Joh 15:13, Joh 15:17, Joh 17:21; Lev 19:18, Lev 19:34; Psa 16:3, Psa 119:63; Rom 12:10; Co1 12:26, Co1 12:27, Co1 13:4-7; Gal 5:6, Gal 5:13, Gal 5:14, Gal 5:22, Gal 6:10; Eph 5:2; Phi 2:1-5; Col 1:4, Col 3:12, Col 3:13; Th1 3:12, Th1 4:9, Th1 4:10; Th2 1:3; Heb 13:1; Jam 2:8; Pe1 1:22, Pe1 3:8, Pe1 3:9; Pe2 1:7; Jo1 4:7-11, Jo1 4:21, Jo1 5:1 John 13:35”