Matthew Poole and continuators on Deuteronomy 16:6

6 But at the place which the LORD thy God shall chuse to place his name in, there thou shalt sacrifice the passeover , at even, at the going down of the sun, at the season that thou camest forth out of Egypt.

To wit, in the Court of the Tabernacle or Temple. This he prescribed, partly that this great work might be done with more solemnity and care in such manner as God required; partly because it was not onely a Sacrament, but also a sacrifice, as appears because it is so called, Exod. 12. 27. and 23. 18. and 34. 25 Numb. 9. 7. and because here was the sprinkling of blood, which is the essential part and character of a sacrifice; and partly to design the place where Christ, the true Passeover or Lamb of God, was to be slain.

Understand this with some latitude, as such phrases are commonly taken, about that season, when you had received command from me to go out of Egypt, and were preparing your selves for the journey.