Rambam - 1 Chapter a Day

Mo’ed Kattan 24a states that this obligation is so forceful that if a person fails to observe it, he is worthy of death.

This command was issued to Aaron and his sons after the death of his two sons, Nadav and Avihu.
The Ramban states that the obligation to rend one’s garments is Rabbinic in origin and the verse is only an asmachta, a support. For the command to Aaron and his sons does not necessarily obligate everyone else. It could be interpreted that Aaron and his sons may not rend their garments, while everyone else is given that option (Radbaz).

The Radbaz states that the Rambam’s wording implies that one does not fulfill his obligation if he rends his garment while seated. In his Kessef Mishneh, Rav Yosef Caro also advances that interpretation and cites other authorities who rule accordingly and he cites this decision in his Shulchan Aruch (Yoreh De’ah 340:1). As such, the person is required to rend his garment again (Ramah).

I.e., King David rent his clothes when he heard a report that his sons had been slain.

From one’s collar.

The Ramah (loc. cit.:2) states that one may rend the lower hem of his garment when rending his garments for deceased persons for whom he is not obligated to mourn (e.g., one was present at the time of a person’s death), but for one’s relatives for whom he is obligated to mourn, he must rend his garments at the front collar.

See Chapter 7, Halachah 6.

Instead, one may leave the border whole and tear only the fabric below it. The Shulchan Aruch (Yoreh De’ah 340:12) quotes this halachah. The Ramah, however, differs and states that one is liable to rend the border for all deceased.

E.g., a knife or a scissors.

Mo’ed Kattan 22b states: “For all other deceased, if one desires one may rend the garment inside or one may rend it outside.” The commentaries offer two interpretations of this statement: a) he may tear the garment in the privacy of his own room (Rashi); b) he may tear only the underside of the garment. It appears that the Rambam accepts both of these interpretations (Kessef Mishneh).

I.e., the leniencies mentioned in the previous clause and in the previous halachah.

I.e., the tear is longer than a handbreadth.
The Jerusalem Talmud (Mo’ed Kattan 3:8) states that this is required because he is losing the mitzvah of honoring his parents which is dependent on the heart.

This additional measure of mourning is included to show the intensity of his grief. See the gloss of the Radbaz to Chapter 9, Halachah 11, which explains that for one’s parents one may uncover either one’s left or one’s right shoulder.
Although the Shulchan Aruch (Yoreh De’ah 340:16) quotes the Rambam’s ruling, the Ramah (loc. cit.:17) writes that it is not customary to uncover one’s shoulder in the present era. This is also the contemporary practice in the overwhelming majority of Sephardic communities today.

I.e., so that others should see and cry over the deceased’s passing (Rashi, Mo’ed Kattan 14b). This applies even when the child is too young to be trained in the observance of the mitzvot (Radbaz).

For we fear that emotional aggravation might be perilous for him.
The Siftei Cohen 337:1 states that even if the sick person knows of his relative’s passing, his garments should not be rent, because the torn garments will continually remind him of his loss.

Lest their mourning make him aware of his loss. The Siftei Cohen 337:2 states that, when a person is dangerously ill, we should not mention the death of any others, even people to whom he is not related, in his presence for that is likely to depress him.

But not because of any of her other relatives (Siftei Cohen 340:6).

He need not rend his garments in the same manner as his wife does. lt is sufficient for him to rend them a handbreadth as one does for deceased other than one’s parents (Radbaz). Although the Shulchan Aruch (Yoreh De’ah 340:4) quotes the Rambam’s ruling, the Ramah explains that this practice is not observed in the present era.

E.g., he was wearing a garment belonging to a colleague (Ramban to Mo'ed Kattan 20b).

For this is after the period of mourning and one’s garments should not be torn afterwards (Mo’ed Kattan 20b).

The Radbaz quotes opinions that mention that for one’s father and mother, one should rend one’s garments for a year. The Shulchan Aruch (Yoreh De’ah 340:18) states that for his father and mother, one should rend his garment “forever.”

Generally, one may not mend a garment torn because of the passing of one’s parent (Chapter 9, Halachah 1). An exception is made in this instance because we are speaking about a borrowed garment (Nimukei Yosej).

Implicit in telling the owner that his father was dangerously ill was the request to tear the garment if necessary. Nevertheless, obviously, he must reimburse the owner for his loss (Mo’ed Kattan 26b).

For he has no permission to rend it. If he tears the garment, he is considered to be stealing it - for he is taking it for a purpose for which he did not notify the owner. Hence, he is considered not to have fulfilled his obligation for rending his garments. See Shulchan Aruch (Yoreh De’ah 340:19).

The Hebrew expression used by the Rambam has a very specific meaning: the amount of time it takes to greet one’s teacher, saying: Shalom eleche, rabbi (Hilchot Sh’vuot 2:17).

Since he died immediately thereafter, it is as if he died at the time the tear was made (Rabbenu Nissim, gloss to Nedarim 87a).

More than it takes to make that statement.

Since the person did not die until some time after the garments were torn, the tearing is not associated with the death. He need not, however, make an entirely new tear; it is sufficient for him to increase the existing tear a handbreadth (see Halachah 12 and notes; Turei Zahav 340:12; Siftei Cohen 240:31). All this applies with regard to other relatives; for one’s parents, he is required to make an entirely new tear.

Without specifying that person’s identity.

Although he rent his garments after the person’s death, since he did not know the true identity of the person who died at the time he rent his garments, he has not fulfilled his obligation.

Or he hears about their death at the same time even though they died at different times [Shulchan Aruch (Yoreh De’ah 340:23)].

Giving them additional honor by showing an extra measure of grief for them. The Radbaz states that if a person loses both his father and mother at the same time, it is sufficient to rend his garments once for both of them.

Other than one of his parents as stated at the conclusion of the halachah.

Ripping the original tear another handbreadth or making a new tear at least three thumbbreadths from the first tear (Kessef Mishneh). For adding to an existing tear is not a sufficient expression of mourning for his relative.

Since the original tear could have been mended by this time, undoing the mend is considered as a new tear if a slight addition is made (Mo’ed Kattan 26b).

If, however, he dies within the week of mourning, he must make a third tear.

In Chapter 9, Halachah 1, which states that one may not mend clothes one tears in mourning for one’s parents.