Numbers 9:8

And Moses said unto them, Stand still, and I will hear what the LORD will command concerning you.

Stand still ... A solution of the difficulty was soon obtained-it being enacted, by divine authority, that to those who might be disqualified, by the occurrence of a death in his family circle, or unable by distance to keep the Passover on the anniversary day, a special license was granted of observing it by themselves on the same day and hour of the following month, under a due attendance to all the solemn formalities (see the note at 2 Chronicles 30:2). But the observance was imperative on all who did not labour under those impediments. This case furnishes a specimen of supplementary legislation, of which various instances will occur in the course of the history.