By the day of unleavened bread of the Passover, He means the fourteenth day of the first month, the day on which, having put away the leaven, they were accustomed to hold the Passover, that is, the lamb, towards evening.
As if to say, We have no abode, we have no place of shelter. Let those hear this, who busy themselves in building houses. Let them know that Christ, the Lord of all places, had not where to lay His head.
To explain this Passover, the Apostle says, Christ our Passover is sacrificed for us. (1 Cor. 5:7.) Which Passover in truth must needs have been slain there, as it was so ordained by the Father’s counsel and determination. And thus although on the next day, that is, the fifteenth, He was crucified, yet, on this night on which the lamb was slain by the Jews, being seized and bound, He consecrated the beginning of His sacrifice, that is, of His Passion.
They prepare the Passover in that house, whither the pitcher of water is carried, for the time is at hand in which to the keepers of the true Passover, the typical blood is taken away from the lintel, and the baptism of the lifegiving fountain is consecrated to take away sin.