Tuesday of Holy Week brings us to the beginning of of Judas' betrayal. He leaves the table, and, in John's account, receives the instruction to do things quickly.
In contrast, Peter boasts to the Lord that he will lay down his life for Jesus. And Jesus tells Peter that that very night, he will deny him three times.
Both are an invitation to mourn. We must never boast, to ourselves or others, in even the most subtle ways, that we are doing great things for the Lord and his Kingdom. For one thing, we aren't. Even if we are doing something, it is God's work, not ours. A healthy sense of holy poverty demands that we not appropriate the graces that God works in the world to ourselves, as if they were some kind of commodity or possession.
Many times we have been Judas, bringing suffering upon even the ones we love because of our attachments and fascinations with of our own agendas and selves. And many times we have been Peter, boasting to our own hearts about the glamorous things we do for God, only to find that, as soon as things become difficult and risky, we don't really want any part of it.