I have often had occasion to refer to the important parallel between the Mishnah in Sanhedrin, Chapter 4 Mishnah 5 and the Qur’an in Chapter al-Ma’ida.
A famous text in Mishnah Sanhedrin, refers to Cain and Abel:
For so have we found it with Cain that murdered his brother, for it says, “The bloods of your brother cry out” (Gen. 4:10). It doesn’t say, “The blood of your brother”, but rather “The bloods of your brother”—meaning his blood and the blood of his descendants. (M. Sanhedrin 4:5)
In other words, the text argues that the wording of Genesis demei “bloods” can be interpreted to include not only Abel but all his potential descendants. They were destroyed, as it were, when he was murdered.
But the Mishna text goes on to apply this to all the descendants of Abel’s father, Adam, that is, everyone—the entire world, not just one line of descendants.
Therefore but a single person was created in the world, to teach that if any man has caused a single soul to perish, he is deemed by Scripture as if he had caused a whole world to perish; and anyone who saves a single soul, he is deemed by Scripture as if he had saved a whole world.
(Readers familiar with the traditional text might notice that I am following the reading of the Mishnah as found in Kafah’s edition of the Commentary to the Mishnah by Moses Maimonides).
This passage was made famous by Steven Spielberg, who quoted it in the beginning of Schindler’s List, and used it in a telling scene in the film, in which Schindler is told about the teaching by the Jews he saved.
The Mishnah text has a parallel in Surat al-Maida in the Qur’an, 5:27…32. It too begins with Adam’s two sons.
And recite to them the story of Adam’s two sons, in truth, when they both offered a sacrifice [to Allah ], and it was accepted from one of them but was not accepted from the other. Said [the latter], “I will surely kill you.” Said [the former], “Indeed, Allah only accepts from the righteous [who fear Him].
But the Qur’an text continues with the discussion of the one son of Adam who murdered the other:
Then Allah sent a crow searching in the ground to show him how to hide the disgrace of his brother. He said, “O woe to me! Have I failed to be like this crow and hide the body of my brother?”
And Cain becomes “regretful.” Is it because of his regret that God made the decree, so similar to the text of the Mishnah?
Because of that, We decreed upon the Children of Israel that whoever kills a soul unless for a soul or for corruption (fasād) [done] in the land – it is as if he had slain mankind entirely. And whoever saves one – it is as if he had saved mankind entirely.
A Christian theologian, Michael Lodahl, pointed out (what seems to me to be ironic!) that the Qur’an refers to a passage from the Mishna as being decreed by God—divine confirmation of traditional Jewish teachings about the ultimate source of the Oral Torah.
But Lodahl’s enthusiasm was not shared by Muslim commentators on the web—a sure indication of the most popular interpretations of the parallel verses—who emphasized the superiority of the Qur’an’s formulation. While it is not particularly surprising to have Muslims assert the superiority of the Qur’an, it should be noted that such discussions typically use the difference in wording to continue the tradition of accusing Jews (along with Christians) of changing or ignoring the text of Divine commands. (Again, confirming the Divine origin of the Oral Torah even if the Jews did not preserve the text correctly!). Moreover, this attitude, and the charge that the pre-Islamic monotheists knew the Divine teachings but sinned, is in the Qur’an itself, which continues: “Then indeed many of them, [even] after that, throughout the land, were transgressors” (5:32).
The context in the Mishnah is warning witnesses in capital cases. The witness whose testimony sends a man to his death is responsible for an irreversible judgment against the defendant, wrongly put to death—and against what he might have done and the children he might have had had he lived. The passage goes on to proclaim yet another advantage of the creation of a single ancestor: no one can claim ancestral privilege over another because ultimately, we all go back to Adam.
In the Qur’an, the context is a condemnation of the Israelites for sowing discord and corruption, for killing without justification, and for transgressing against God. The introduction to this passage refers to the people of Moses—the Children of Israel—being disobedient (fāsiqīn), and follows this verse with a reference to those who spread corruption (fasād), part of a motif in al-Ma’ida about the previous nations who had had covenants with God but broke them and did evil in the land.
So, with its reference to Cain and Abel, the destruction of future generations, and the statements about those who cause the death or preservation of a single person—even the reference to the crow—this Qur’an passage reflects the Mishna and other well-known Jewish texts. And, as Lodahl observed, the Qur’an text can be seen as confirmation of the divine origin of the Oral Law. But the Qur’an text is not linked with testimony in capital cases; while it is often understood in ways similar to the Mishna text (and to the way it is used in Schindler’s List), it also appears to fit in with the Qur’an’s approach to the Jews, and other ancient nations, that had had prophetic guidance and a divine covenant, but which it now sees as either vanished or superseded.
 On this interpretation of “bloods,” see also Gen. Rabbah 22:9, Targums Onkelos, Neofiti, and Jerusalem Fragment targum on Gen. 4:10.
 On the crow teaching Adam how to bury: See Pirqe d’Rebbe Eliezer 21 towards the end. In this text, Adam learns how to bury by watching the crow. http://www.daat.ac.il/daat/vl/pirkeyeliezer/pirkeyeliezer03.pdf http://he.wikisource.org/wiki/%D7%A4%D7%A8%D7%A7%D7%99_%D7%93%D7%A8%D7%91%D7%99_%D7%90%D7%9C%D7%99%D7%A2%D7%96%D7%A8_%D7%A4%D7%A8%D7%A7_%D7%9B%D7%90
 Michael Lodahl, Claiming Abraham: Reading the Bible and the Qur’an Side by Side. Grand Rapids: Baker Pub. Group, 2010.