What were the requirements for the Passover lamb?
The Passover lamb had to be a male of the first year, without blemish, taken from the sheep or goats on the tenth day of the first month and kept until the fourteenth. Each household was to take a lamb; if too small, it was shared with a neighbor, with enough for all according to each person's eating.
Les explains that the first month was the beginning of Israel's religious year, and on the tenth day every man was to take a lamb according to the house of his fathers, a lamb for a house. If a household was too little or too small for the lamb, he and his neighbor next to his house were to take it according to the number of souls, every man according to his eating. There was never to be a shortfall; there was always supposed to be enough. The lamb had to be without blemish, a male of the first year, taken from the sheep or from the goats, and kept or penned up until the fourteenth day of the same month. Les also presents this as a beautiful illustration of the Lord Jesus, who was without spot, without blemish, and without sin.
Your lamb shall be without blemish, a male of the first year: ye shall take it out from the sheep, or from the goats:
And ye shall keep it up until the fourteenth day of the same month: and the whole assembly of the congregation of Israel shall kill it in the evening.