Exodus 12:3

Speak ye unto all the congregation of Israel, saying, In the tenth [day] of this month they shall take to them every man a lamb, according to the house of [their] fathers, a lamb for an house:

Ver. 3. In the tenth day.] The paschal lamb was taken up the tenth day, but not sacrificed till the fourteenth, that they might "so kill the passover" as first to "sanctify themselves and prepare their brethren." 2Ch 35:6 For which cause also it was a received tradition among the Jews, that during those four days the lamb was tied to their bedposts. a

a Hospin., De Orig. Fest., cap. 5.