Charles Ellicott Commentary Mark 14:12

"And on the first day of unleavened bread, when they sacrificed the passover, his disciples say unto him, Where wilt thou that we go and make ready that thou mayest eat the passover?" — Mark 14:12 (ASV)

And the first day of unleavened bread.—See Notes on Matthew 26:20-25.

When they killed the passover.—Better, when they used to sacrifice; the Greek tense implying a custom. Here, again, both St. Mark and St. Luke write as explaining the custom for their Gentile readers.