Shulchan Arukh, Yoreh De'ah 360

<b>מת וכלה ומילה איזה קודם. ובו סעיף אחד:</b><br>אם פגעו מת וכלה זה בזה מעבירין המת מלפני הכלה וכן אם אין בעיר כדי לזה ולזה מקדימין ומכניסין הכלה לחופה ואחר כך קוברים המת אבל אחר שנכנסה לחופה ויש לפניו לנחם אבל ולשמח חתן תנחומי האבל קודם וכן הבראת האבל קודם למשתה של חתן במה דברים אמורים שיש בידו ספוק כדי שניהם אבל אם אין בידו כדי שניהם משתה החתן קודם. (חתן ואבל בב"ה יוצא החתן עם שושביניו תחילה ואחר כך האבל והמנחמים וכן הקרואים שלהם אוכלים עם החתן כשירצו ולא עם האבל) (ב"י בשם הגהות מיימוני פ"ד) . המת והמילה מילה קודמת ואם הוא מת מצוה מת מצוה קודם:

If a funeral procession and a bridal procession meet each other [on the way], the funeral procession is made to make way for the bridal procession.. A precept, the fulfilment of which serves the living, takes precedence over one which serves the dead. The main purpose of ‘bringing in the bride under the bridal canopy’ ( הכנסת כלה לחופה ) is on account of procreation, as it is written, ‘ He created it (i.e., the world) not a waste . He formed it to be inhabited ’ (Is. XLV, 18) — ShaK . Likewise, if there are not sufficient [people] in the city [to attend] both, they bring in the bride [under the bridal] canopy first, and then they bury the dead; and N in T.H. derived from Sem(H). XI, 6. but after she has been brought in [under the bridal] canopy and there is before him [the duty] to comfort a mourner and to gladden a bridegroom, comforting the mourner comes first. Similarly the mourners' meal takes precedence over the bridegroom's [wedding-] feast.. p. 231 and Int. p. 20; Yad. Ebel XIV, 8 and comment.; She’iltoth Gen. § 50 end. The reason for this ruling is that in the case of a groom he eats of his own and serves others as well; whereas a mourner does not eat until others prepare the first meal for him — ShaK. When does this apply? — When one has the means to fulfil both [religious duties]; but if he does not possess the means to fulfil both, the bridegroom's [wedding-] feast comes first. n. 3. Tur and Caro follow N in T.H. (v. supra n. 5) and hold that both in the case of the two processions meeting each other and in the case of attending a burial and a marriage where there are not sufficient people to attend to both, the law is that a marriage ceremony takes precedence. It is only in the case where the wedding ceremonies had already taken place that visiting the house of mourning takes precedence over the wedding-feast that follows the marriage. This applies only if the duty of attending the wedding-feast will not be neglected entirely, but should one not be able to attend to both, as a result of which, one precept will be completely neglected, attending the wedding-feast takes precedence. Cf. however, Yad, Ebel XIV, 8 according to which a bride takes precedence over a corpse only where the two processions meet each other, but otherwise, one must attend to the needs of the corpse first — A.H. also B.Yos. and W.G. who had a different reading in Sem. ibid. [ If ] a groom and a mourner are in the Synagogue, the groom and his friends leave first and then the mourner and the comforters; and thus [ also ] their guests may eat with the groom if they so desire, and not with the mourners , on the authority of Hag. Maim. Yad, Ebel XIV, 8 — G. also Ket. 17a, Tosaf. s.v. ת״ר . The latter add: ‘And thus in the morning when they lead the bride to the groom’s home, they lead the bride first if there is a corpse (awaiting burial) in the city. Or they bury him before the time of the wedding ceremonies arrives.’ . [In the case of] a corpse and a circumcision,—circumcision comes first. in T.H. supra n. 3. If, however, he is a corpse [the burial of which] is a religious duty, he comes first. takes precedence over everything, e.g., bringing a bride to the canopy; the study of the Torah; the Temple service; the reading of the Megillah (Scroll of Esther) ; overrides defilment etc. (Meg. 3b). Cf. infra § 374, 3; O.Ḥ. § 687 end; Yeb. 89b; Naz. 43b, Tosaf. s.v. האי מת מצוה — Be’er ha-Golah, ShaK.