1. Why did he not command them concerning the love of God, which is the first and greatest commandment ?
2. Likewise, how does he say new, since it was given from the beginning? Whence in the second chapter of First John, speaking of this commandment, he says: I do not write a new commandment to you, but an old commandment.
I respond: To the first it must be said that in the love of neighbor the love of God is understood.
To the second it must be said that even though this commandment was given in the Old Testament, nevertheless in the New it is renewed with respect to its mode: because there to love friends, here enemies; there to do good to friends, here to enemies is commanded; this is what he implies when he adds: As I have loved you.
55. Question IV. Likewise it is asked concerning what the Lord said to Peter: You will deny me three times. From this it seems that he revealed to Peter his fall, and that he compelled Peter to despair.
I respond: It must be said that to foretell and to reveal are different. God reveals to no one, but nevertheless He does foretell: because what is revealed is known with certitude, but what is foretold is not: because sometimes it is believed to be said as a threat, and sometimes under a condition. Whence Peter also understood it under a condition: if you do not guard yourself; and therefore he did not despair.