Numbers 9:4

2 “The Israelites are to observe the Passover at its appointed time.

3 You are to observe it at the appointed time, at twilight on the fourteenth day of this month, in accordance with its statutes and ordinances.”

So Moses told the Israelites to observe the Passover,

5 and they did so in the Wilderness of Sinai, at twilight on the fourteenth day of the first month. The Israelites did everything just as the LORD had commanded Moses.

6 But there were some men who were unclean due to a dead body, so they could not observe the Passover on that day. And they came before Moses and Aaron that same day

This was said to Israel at a particular time, so it is wise to read it together with the surrounding text. Do read the surrounding verses too, because the context often says more than a single verse.

Compare

BSB
So Moses told the Israelites to observe the Passover,
KJV
And Moses spake unto the children of Israel, that they should keep the passover.
WEB
Moses told the children of Israel that they should keep the Passover.
ASV
And Moses spake unto the children of Israel, that they should keep the passover.
DARBY
And Moses spoke to the children of Israel, that they should hold the passover.
BLB
And Moses spoke to the sons of Israel, that they should keep the Passover.
ÅB
Da talte Moses til Israels barn og sa at de skulle holde påske.
OTB
Så instruerte Moses israelittene om å holde påsken.
B1930
Da talte Moses til Israels barn og sa at de skulde holde påske.

Study notes (Tyndale)

Original text and word study