Numbers 9:3

9:3 In the fourteenth day of this month, at twilight, ¹  you are to observe it at its appointed time; you must keep ²  it in accordance with all its statutes and all its customs.” ³ 

Numbers 9:11

9:11 They may observe it on the fourteenth day of the second month ⁴  at twilight; they are to eat it with bread made without yeast and with bitter herbs.

[9:3]  ¹ tn The literal Hebrew expression is “between the evenings” (so also in vv. 5, 11). Sunset is certainly one evening; the other may refer to the change in the middle of the afternoon to the late afternoon, or the beginning of dusk. The idea is probably just at twilight, or dusk (see R. B. Allen, TWOT 2:694).

[9:3]  ² tn The two verbs in this verse are identical; they are imperfects of instruction. The English translation has been modified for stylistic variation.

[9:3]  ³ tn The two words in this last section are standard “Torah” words. The word חֹק (khoq) is a binding statute, something engraved and monumental. The word מִשְׁפָּט (mishpat) means “judgment, decision,” but with a more general idea of “custom” at its core. The verse is making it very clear that the Passover had to follow the custom and form that was legislated in Egypt.

[9:11]  ⁴ sn The delay of four weeks for such people would have permitted enough time for them to return from their journey, or to recover from any short termed defilement such as is mentioned here. Apart from this provision, the Passover was to be kept precisely at the proper time.