Exodus 12:3-4

12:3 Tell the whole community of Israel, ‘In the tenth day of this month they each must take a lamb for themselves according to their families – a lamb for each household. 12:4 If any household is too small for a lamb, the man and his next-door neighbor are to take a lamb according to the number of people – you will make your count for the lamb according to how much each one can eat.