According to all the ordinances - i. e. those relating to the Passover lamb, not those concerning the feast, for the Little Passover lasted, according to the Jews, only one day; nor was it held to be needful that at it leaven should be put away out of the houses.
Related Commentaries of Numbers 9:12
Numbers 9:12
12 They shall leave none of it unto the morning, nor break any bone of it: according to all the ordinances of the passover they shall keep it.