Exodus 34:25

‘And they shall eat the flesh that night, roasted with fire, and they shall eat it with unleavened bread and bitter herbs.

‘And you shall not leave any of it over until morning, but whatever is left of it until morning, you shall burn with fire.

“You shall not offer the blood of My sacrifice with leavened bread; nor is the fat of My feast to remain overnight until morning.

“If any of the flesh of ordination or any of the bread remains until morning, then you shall burn the remainder with fire; it shall not be eaten, because it is holy.

‘No grain offering, which you bring near to Yahweh, shall be made with leaven, for you shall not offer up in smoke any leaven or any honey as an offering by fire to Yahweh.

“For seven days no leaven shall be seen with you in all your territory, and none of the flesh which you sacrifice on the evening of the first day shall remain overnight until morning.