Matthew 5:28
27 “You have heard that it was said, ‘Do not commit adultery.’ 28 But I say to you that whoever looks at a woman to desire her has already committed adultery with her in his heart. 29 If your right eye causes you to sin, tear it out and throw it away! It is better to lose one of your members than to have your whole body thrown into hell. 30 If your right hand causes you to sin, cut it off and throw it away! It is better to lose one of your members than to have your whole body go into hell.
Niddah 13b
Babylonian TalmudThe Gemara suggests: Come and hear, as it is taught in a baraita that Rabbi Tarfon says: If one’s hand goes to his penis, his hand should be severed upon his navel. The Rabbis said to him: If so, in a case where a thorn was stuck in one’s belly, should he not remove it? Rabbi Tarfon said to them: Indeed, he should not remove it, and if he does so his hand should be severed. The Rabbis replied: But if his hand is severed while it is upon his navel, won’t his belly be split open? Rabbi Tarfon said to them: It is preferable that the belly of one who acts in this manner should be split open, and he should not descend into the pit of destruction.
Notes and References
"... The sort of relationship I am maintaining exists between b. Niddah 13b and Mark 9:42-48 is even more in evidence in the case of Matt 5:27-30. Here we not only find the sayings about the offending eye and hand, and the phrase 'it is of benefit to you that one of your members should perish and that your whole body should not be thrown into hell (verse 29, 30)', the syntax of which is even closer to its rabbinic counterpart than the Markan but now the saying about the offending eye follows immediately on an antithesis that equates lustful glances with adultery (verses 27-28). In other words, the saying about the eye now appears explicitly in the type of sexual context that I postulated for the sayings in Mark 9. This antithesis, moreover, is important in its own right, for it too comes remarkably close to material in b. Niddah 13b. It opens with a citation of the seventh commandment against adultery, and then proceeds with a midrash on this commandment, the purpose of which is to broaden its meaning so as to include lustful glances under the rubric 'adultery'. This is precisely the structure of the passage in b. Niddah 13b that recounts the view held by R. Ishmael's school ..."
Deming, Will Mark 9:42-10:12, Matthew 5:27-32, and b. Nid. 13b: a First Century Discussion of Male Sexuality (pp. 130-141) New Testament Studies, 36, 1990