Lamb. Hebrew se, which denotes the young of either sheep or goats. (Kimchi) He who had not a lamb, was to sacrifice a kid. (Theodoret)

A kid. The Phase might be performed, either with a lamb or with a kid; and all the same rites and ceremonies were to be used with the one as with the other. (Challoner)

Many have asserted, that both were to be sacrificed. But custom decides against them. All was to be perfect, Momim, as even the pagans required; (Grotius) and God (Leviticus xxii. 22,) orders the victims in general must have no fault. The Egyptians rejected them, if they were even spotted, or twins.

A male, as all holocausts were to be. Pagans gave the preference to females. (Calmet)

One year, not older, though it would do if above eight days old. (Menochius)

The paschal lamb prefigured Jesus Christ, who has redeemed us by his death, being holy, set apart, and condescending to feed us with his sacred person, in the blessed Eucharist. Here we eat the lamb without breaking a bone, though we take the whole victim. (John xix. 36; 1 Corinthians v. 7.) (Calmet)

To fulfil this figure, Christ substituted his own body, and, making his apostles priests, ordered them to continue this sacrifice for ever. He came to Jerusalem on the 10th day of Nisan, on Sunday. He gave himself to his disciples on the evening of the 14th, and died at noon on the 15th. The unleavened bread, and the cup, (Luke xxii. 17,) clearly denoted the blessed Sacrament, which was ordered to be eaten in the house or church of God. (St. Cyprian, Unit.) See St. Gregory, hom. 22, in Evang.; Tertullian, contra Marc. iv, “The bread he made his own body.” If, therefore, the truth must surpass the figure, surely the blessed Sacrament must be more than bread and wine; otherwise it would yield in excellence and signification to the paschal lamb. (Worthington)