Reference for Moed Katan 40:15
אלא לאו שמע מינה כאן בחמיו וחמותו כאן בשאר קרובים שמע מינה תניא נמי הכי לא אמרו לכבוד אשתו אלא חמיו וחמותו בלבד
[Now the regulations in] the two citations contradict each other.<span class="x" onmousemove="('comment',' In the former it is insisted that the husband must observe formal mourning out of deference to the wife, while in the latter, it implies that the husband need not.');"><sup>27</sup></span> Hence infer from this that the one Baraitha refers to [the death of] a father-in-law or mother-in-law,<span class="x" onmousemove="('comment',' In which case he must mourn with her.');"><sup>28</sup></span> while the other to [the death of] other near of kin.<span class="x" onmousemove="('comment',' In which case he need not mourn with her.');"><sup>29</sup></span>