The cross is the place of glory
The washing of the disciples’ feet by Jesus lays the foundation for the long section of teaching he is about to give them but first he tells them of his imminent betrayal by Judas (13:18-30). The disciples are shocked and mortified to hear of this, but the shock would have been greater if he had not prepared them for it (19). Just as the coming of some Greeks had been a sign to Jesus that the time had come for him to be glorified (12:20,23), so the going out of Judas is likewise a key moment which confirmed that the time for his death was now very near (31).
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The glory of the Father and the Son cannot be separated; both would receive glory through Jesus’s death (32; 12:28). The words now (31) and at once (32) emphasise that the time for this had come. So, with much affection (my children), Jesus begins the instructions that will prepare his disciples for his departure, and for what they then must do (33).
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The cross is a place of glory, because it is there that his saving work was accomplished, opening the way for his return to the Father (13:1). But that’s the beginning, not the end, of his work, and what he goes on to teach his disciples will equip them (and us) to do his mission in this world.