Deuteronomy 16:4-6

New Revised Standard Version, Anglicised Catholic Edition

⁴ No leaven shall be seen with you in all your territory for seven days; and none of the meat of what you slaughter on the evening of the first day shall remain until morning. ⁵ You are not permitted to offer the passover sacrifice within any of your towns that the Lord your God is giving you. ⁶ But at the place that the Lord your God will choose as a dwelling for his name, only there shall you offer the passover sacrifice, in the evening at sunset, the time of day when you departed from Egypt.