"Could not keep"

1. Num. 9: 6
   6 ¶ And there were certain men, who were defiled by the dead body of a man, that they could not keep the passover on that day: and they came before Moses and before Aaron on that day:
2. 2 Chr. 30: 3
   3 For they could not keep it at that time, because the priests had not sanctified themselves sufficiently, neither had the people gathered themselves together to Jerusalem.
3. 1 Ne. 4: 15
   15 Yea, and I also thought that they could not keep the commandments of the Lord according to the law of Moses, save they should have the law.