From The Crucifixion of the Paschal Lamb by Joseph Tabory, in The Jewish Quarterly Review , New Series, Vol. 86, No. 3/4 (Jan. – Apr., 1996), pp. 395-406. via JSTOR.

Justin Martyr depicted the paschal lamb as being offered in the form of a cross and he claimed that the manner in which the paschal lamb was slaughtered prefigured the crucifixion of Jesus. It is generally thought that Justin, who was born and raised in Samaria, was thinking of the Samaritan Passover, but the present day Samaritan practice would not justify his depiction of the lamb in the form of a cross. An examination of the rabbinic evidence, on the other hand, seems to show that in Jerusalem the Jewish paschal lamb was offered in a manner which resembled a crucifixion. The earlier Samaritan practice, it is suggested, followed the Jerusalem tradition but has since been changed. The rabbinic evidence could also provide an explanation for the crown of thorns with which Jesus was adorned.

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Justin notes that there were two spits used in the sacrifice, one parallel to the spine and another attached to the back of the which prefigured the crossbar of the cross…

In modern Samaritan custom, after the lamb is spitted along its spine, it is held in a position perpendicular to the ground, with its head down. A wooden collar is attached to the bottom end of the spit to prevent the lamb from sliding off. Moulton remarked that the spit which he saw in 1903 “has little resemblance to the shape of the cross alluded to by Justin Martyr.” Presumably he is referring to the spit parallel to the spine. However, there is another horizontal rod or pole clearly evident in the photographs of the Samaritan paschal lamb published by Jeremias in 1932. The lamb is hung by its feet from this pole immediately after it is slaughtered, and it is thus held between the shoulders of two men while it is being cleaned and while its right leg is removed as an offering to the priest. The lamb is held in this manner until the roasting spit is inserted parallel to its spine. The pole was apparently removed afterwards, but for a short period this lamb was actually attached to two pieces of wood which had the shape of a cross.

Such a second pole is also documented in talmudic literature. Although the Mishnah reports that the paschal lamb was generally hung from hooks while it was being flayed, it also dictates an alternate procedure when a large number of lambs exhausted the supply of hooks. There were a number of short, thin poles or rods which were kept in the Temple for such an occasion. Two people would stand next to one another and put a rod between their shoulders; they would then suspend the paschal lamb from this rod while a third person would flay it (mPes 5.9)…

A modern reconstruction of the paschal oven portrays it in the form of a beehive, about twice as tall as it is wide and with a curved roof. This portrayal is probably accurate as it would be difficult to build a long, roofed object out of unfired clay. One would need some sort of support, such as rails or beams, to support the clay on the roof, or the oven would have to be constructed with an arched roof… The pictures of ovens in the Encyclopedia Hebraica, s.v. tanurim, show beehive shaped ovens. The shape and size of the talmudic oven make it most likely that the lamb was placed upright in the oven…

The custom of carrying the lamb with its head upright could explain another point in Jewish tradition, and this explanation may, in turn, shed light on the origin of this custom. The Bible tells us that the ram which was offered on the altar in place of Isaac was “caught in the thicket by its horns” (Gen 22:13). Mark Bregman has pointed out that Jewish art did not portray this lamb as if standing on its four legs, but as hanging from the tree by its horns, much as Avshalom was held between heaven and earth when his hair was caught in a terebinth (2 Sam 18:9). The question is why the lamb was portrayed in this unusual position, which does not seem to be dictated by the biblical description of the lamb. Bregman suggests that this description was influenced by Christian art, which illustrates the patristic typology of the ’aqedah as a prefiguration of the crucifixion of Jesus. Bregman discusses the possibility that the artist was relying on a Jewish midrashic tradition, but he does not consider this explanation as likely as the one based on Christian theology. Now, the depiction of the lamb of Isaac is lacking an essential element for a prefiguration of the crucifixion: there is no crossbar. However, in light of our analysis of the way in which the paschal lamb was carried and roasted, it may be noted that the position of the lamb of Isaac is almost identical to that of the paschal lamb. Jewish tradition was aware of an affinity between the lamb of Isaac and the paschal lamb…

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