Commentary for Moed Katan 3:7
אֵין קוֹרְעִין, וְלֹא חוֹלְצִין, וְאֵין מַבְרִין, אֶלָּא קְרוֹבָיו שֶׁל מֵת, וְאֵין מַבְרִין אֶלָּא עַל מִטָּה זְקוּפָה. אֵין מוֹלִיכִין לְבֵית הָאֵבֶל לֹא בְּטַבְלָא וְלֹא בְאִסְקוּטְלָא וְלֹא בְקָנוֹן, אֶלָּא בְסַלִּים. וְאֵין אוֹמְרִים בִּרְכַּת אֲבֵלִים בַּמּוֹעֵד, אֲבָל עוֹמְדִין בְּשׁוּרָה וּמְנַחֲמִין וּפוֹטְרִין אֶת הָרַבִּים:
Only the close kin of the dead one rend (their garments), bare (their shoulders), and are given the mourners' meal [on Chol Hamoed. (The above are performed for) father and mother, son and daughter, brother and sister, and wife. These are the seven for whom one must mourn. One does not rend his garments on Chol Hamoed for other kin, for whom he is not obligated to mourn. This, only if he were not a sage or a G d - fearing man and a doer of mitzvoth. But all are the kin of a sage who died, and all rend their garments over him, even on Chol Hamoed, and, likewise, for one who was known to be upstanding and saintly. And all who stand at the expiration of the soul of any Jew must rend their garments, even on Chol Hamoed. Rending for father and mother is (rending of) all his garments, until he bares his heart. He tears with his hand and separates the upper edge of the garment and rends it from the outside, not inserting his hand beneath his garments as he does so. He may baste them after thirty days, but he may never sew them together. And so, with his teacher who taught him Torah. But for his other kin he tears a handbreadth of the outer garment alone. And he may rend with an instrument if he desires and he need not separate the edge, and he may insert his hand under his garments when he rends. And he bastes after shivah and sews together after shloshim. Rending is done only while standing. And there is no baring of arms and shoulders on Chol Hamoed. The mourners' meal is the first meal (after the burial), which the mourner may not prepare for himself and which others provided for him in the open place of the city. And on Chol Hamoed only his kin have the meal (and not in the open place, but) in his house.] And the mourners' meal is eaten only on an upright bed. [Even in his house, he is not served the mourners' meal on an overturned bed. For all of his kin and close acquaintances would regularly eat (the mourners' meal) with him on an overturned bed; but on Chol Hamoed they would eat it only on an upright bed.] The mourners' meal is not brought [to the mourner's house] on a tray ["honorifically"] or on a salver [of silver, gold, or glass. I have heard (it interpreted as) a silver dish.], or in a reed basket, but in a basket [of peeled willow, so as not to embarrass the poor who come to bring the meal and who have neither tray nor salver.] And the mourners' blessing is not recited on Chol Hamoed, but they stand in a row and console (the mourners), and those assembled there are permitted to leave immediately.
Bartenura on Mishnah Moed Katan
English Explanation of Mishnah Moed Katan
And they do not provide a meal except on an upright couch.
They do not bring [food] to the house of mourning on an [ornamental] tray, platter, or flat basket, but in plain baskets.
And they do not say the mourners’ blessing during the festival.
But they may stand in a row and comfort [the mourners] and [the mourners] may formally dismiss the community. Section one: When one heard that a close relative had died, one would rend whatever clothes they were wearing. Baring the shoulder was also a sign of mourning. The mourner was provided by the community with the first meal after the funeral. On Hol Hamoed only a close relative would perform these practices. Others would not. I should note that today only close relatives do these actions in any case. The circle of mourners was bigger in the Talmudic period. Section two: It was customary to overturn the bed during mourning and then sit on the bed as a sign of mourning. But one does not overturn the bed during Hol Hamoed. This practice fell into disuse sometime after the Talmudic period. Section three: This halakhah is true in all cases. When bringing food to the mourner, they should bring it in plain baskets. A source in the Talmud relates that originally people would use fancy silver and gold vessels, but poor people would be embarrassed that they could not afford such fancy funerals and mourning homes. As a response the rabbis decreed that everyone must bring in a simple vessel. The mourning home is not a place where one should be showing off one’s wealth. Section four: The mourners’ blessing was stated on return from burial. They would stand in a line and comfort the mourner with this blessing. It may have also been recited at other points as well. But it is a public sign of mourning and should not be done on Hol Hamoed. Section five: While the blessing is not recited on Hol Hamoed, burial is. Along with the burial, they may have the formal line of comforters that would accompany the mourners on their way home. The same goes true for the official words that the mourner seems to have said to the comforters, to allow them to go home without accompanying the mourner all the way home.
Today’s Mishnah discusses mourning practices not observed during Hol Hamoed. It is interesting to note that this Mishnah is one of the main sources of the laws of mourning. It seems, at least to me, that the Mishnah did not feel it was necessary to teach people how to mourn. People just knew what to do. The only reason they are mentioned is to let people know when not to observe these practices.