The Decision of the Chief Priests. Two days before the Passover, i.e. on Wednesday, if the feast day began on Friday at even, the religious leaders resolve to destroy Jesus, if possible before the feast begins. This decision explains the haste which marks the closing scenes. It also gives the preference to John's view that the Last Supper was not held on the Passover night, but on the night before (pp. 653, 743, 1 Corinthians 5:7 b*).
Mark 14:1. The seven days of unleavened bread followed the Passover (pp. 102f.). For the coupling of the two cf. 2 Chronicles 35:17.