ISB ~ 1 John 2 v7

no new commandment:John’s teaching is not a recent innovation unfamiliar to his readers. It is, rather, the commandment to love one another (2:10) that they received with the gospel and that ultimately goes back to Jesus (Jn 13:34). The point is that John’s catechesis is an authentic expression of apostolic doctrine (CCC 2822). See note on Jn 13:34.