Mark 14:10-12

10Then Judas Iscariot, one of the Twelve, went to the chief priests to betray Jesus to them. 11They were delighted to hear this, and they promised to give him money.

So Judas began to look for an opportunity to betray Jesus.

12On the first day of the Feast of Unleavened Bread,1 when the Passover lamb was to be sacrificed, Jesus’ disciples asked Him, “Where do You want us to prepare for You to eat the Passover?”