Translation:Shulchan Aruch/Yoreh Deah/374
Seif 4: All the relatives for whom a kohen must become impure – his father, his mother, his son, his daughter, his brother and his virgin sister through his father, and his wife – one mourns them. They [i.e. the sages] further added to them – his brother from his mother, his sister from his mother whether a virgin or married and his married sister through his father – one mourns for them, even though a kohen may not become impure for them. Also, just as one mourns for his wife, thus also she mourns for him [her husband] – but only for his wife who is permitted to him and who is married, but if she is forbidden to him or [only] betrothed, one does not [mourn]. However, for his son, his daughter, his brother and his sister – even though they are [from an] invalid [pairing], he mourns them, except for his son, his daughter, his brother or his sister from a maidservant or a gentile – he does not mourn them.
Seif 5: A convert who converted to Judaism, he and his children, or a slave who is emancipated, he and his mother, they do not mourn each other. {Rema: And this is the rule also for a convert who converted to Judaism with his mother, they do not mourn for each other}.
Seif 6: All whom one mourns, he mourns with him if a relative [of the latter, i.e. the one for whom the first would mourn were the latter to die] dies. But this is only in his presence, but when not in his presence, it is not necessary to conduct mourning rituals. [However, this is true] other than with regard to his wife, who, even though he would mourn over her, he does not mourn with her, except for her father or her mother because of [the mitzvah of] honoring one's father-in-law and mother-in-law, but over her brother and sister or her son and daughter from another man, one does not mourn with her. But in any event, he cannot force her to adorn herself, but she can mix a cup for him and make his bed and wash his face and hands and legs. And similarly, she does not mourn with him, except for when her father-in-law or mother-in-law dies, but other of his relatives who die, she does not mourn with him. {Rema: And there are those who say that nowadays, the practice is to be lenient in this mourning with those for whom one would mourn, because this is only for the honor of the mourners, and nowadays all of them relinquish their honor. And thus the practice nowadays is not to mourn at all with those for whom one would mourn, and all who are strict with regard to this are considered shocking. But in any event, the practice is that all the relatives of the dead person who are forbidden to him as witnesses indicate a little of mourning themselves for all of the first week. That is to say, until after the first Shabbat, they do not wash and they do not change some of their clothing as they would on other Shabbatot. And there are places where the practice is to be stringent in other ways, but the essence is like I wrote. And all this is for word of a death that arrived soon after the death, or who was at the house when he died, but one who long after the death, there is no place for this mourning at all. [But] one who wants to be stringent for himself to mourn one for whom it is not necessary or to wear black on account of his relative, we do not prevent him}.
Seif 7: One does not mourn with his relatives for whom one would have to mourn [who are mourning over their dead] except for when they are mourning over a blood relative – e.g. his son or his brother when they mourn over the son or daughter of one of them – but over the marital relatives of them – e.g. when the wife of his son or the wife of his brother or the husband of his daughter or the husband of his sister dies, he does not mourn over them.
Seif 8: A baby for all the first thirty days, and including the thirtieth day, one does not mourn for him even if his hair or his nails finished [coming in]. But from then onward, one mourns for him unless it is known that he was born after eight (months of gestation which would be considered unviable). But if one can trust that his months were completed, as in a case when he had sex and then separated and it was born alive after nine complete months, even if the baby died on the day it was born, one mourns over it. (If there is a doubt whethera child is [the product] of 9 months [of gestation] to the first [husband] or seven to the last [husband] the two of them (i.e. both potential fathers) mourn over him.