Exodus 12:4

If the household. At a later time Jewish tradition fixed at ten the number of persons for whom one lamb was to be apportioned, and said also that all members of the family, men, women and children, must participate in the activities of the feast. The lamb, according to Jewish sources, was usually slain between the 9th hour (c. 3 P.M.) and the 11th hour (c. 5 P.M.).

Every man according to his eating. When provision was made for those who were to participate, consideration was to be given to the amount each one would be likely to eat. Children and the aged were not to be counted in the same way as men in the vigor of life. Consequently, more than two families might unite for this purpose.