Charles Ellicott Commentary Numbers 9:13

"But the man that is clean, and is not on a journey, and forbeareth to keep the passover, that soul shall be cut off from his people; because he offered not the oblation of Jehovah in its appointed season, that man shall bear his sin." — Numbers 9:13 (ASV)

Shall bear his sin —i.e., shall be put to death. (Numbers 18:22.)