[If one says:] “I am a nazir, and it is [an obligation] upon me [to provide for] a nazir to shave [his head],” and his friend heard [him] and said, “And I, and it is [an obligation] upon me [to provide for] a nazir to shave [his head]” —- if they are clever, they [provide for] each other [to] shave, and if not, they [must provide for] other nezirim [to] shave.

[If he says:] “It is [an obligation] upon me [to provide for the] shaving of half a nazir,” and his friend heard [him] and said, “And I, it is [an obligation] upon me [to provide for the] shaving of half a nazir” —- this one must [provide for the] shaving of a complete nazir, and this one must [provide for the] shaving of a complete nazir; [these are] the words of R’ Meir. But the Sages say: This one provides half [of the sacrifices needed] to shave a nazir, and this one provides half [of the sacrifices needed] to shave a nazir.

7. [One who says:] “I am a nazir when a son will be [born] to me,” and a son was born to him —- he is a nazir. [If] a daughter, or one of unknown gender, or an androgyne was born to him —- he is not a nazir. If he said: “When I shall see that there will be [born] to me a child” —- even [if there] is born to him a daughter, or one of unknown gender, or an androgyne —- he is a nazir.

[If] his wife lost the baby, he is not a nazir. R’ Shimon says: He should say: “If it was [a] viable [child], I am a nazir by [previous] obligation, but if not, I am a nazir voluntarily.” [If] she again gave birth, he is a nazir. R’ Shimon says: He should say: “If the first was viable, the first [nezirus] was obligatory, and this one is voluntary; but if not, the first [nezirus] was voluntary, and this one is obligatory.”