Although the Mishnayot of the third perek begin with a discussion of Hol HaMoed – and specifically the rules that regulate washing clothing, taking haircuts and writing during that time – the Gemara chooses to move the conversation in the direction of two other circumstances that have similar halakhot: aveilut (mourning) and nidduy (a ban or excommunication of sorts). The connection to these halakhot stems both from the similarity between the restrictions of Hol HaMoed and these circumstances, as well as from the need to determine appropriate behavior when they coincide (for example, when a person becomes a mourner on, or immediately before, Yom Tov).
Many of the laws that apply to aveilut are mentioned in the TaNaKH, and over the generations they have developed into a code of accepted tradition. Nevertheless, given that these halakhot do not appear listed formally in the Torah, many practical questions arise as to what is required and what is simply tradition, when and how exactly certain practices should – or must – be done.
One text-source that is used by the Gemara in determining accepted practice for Jewish mourning is the passage in Yehezkel 24:15-17, where the prophet Yehezkel is informed by God that his most beloved will be taken away in a plague, yet he should not behave as a mourner ordinarily does. He is told that while remaining silent he should keep his head normally attired, continue wearing his shoes, refrain from covering his mouth and not accept meals from others.
From the fact that Yehezkel is commanded pe’erkha havush alekha – to retain his pe’er on his head – the Gemara understands that other aveilim are not supposed to wear tefillin (for the first day of aveilut).
The Gemara continues: A mourner is prohibited from greeting others or be greeted. This is derived from the fact that the Merciful One says to Yehezkel: “Sigh in silence [hay’anek dom]” (Yehezkel 24:17), implying that aside from what was absolutely essential, he was prohibited from speaking.
The difficulty with this Gemara is that Yehezkel is commanded to behave as if he is not a mourner, so how can we learn from his need to be silent that an avel cannot exchange greetings? Several approaches are suggested by the rishonim –
The Ra’avad points out that the commandment to behave normally appears after the statement hay’anek dom (see pasuk – verse – 17) suggesting that silence is one mourning activity that is permitted to him.
Others maintain that the correct interpretation of the passage is that Yehezkel is being told that he should neither remain silent, nor should he do any other activities that make him appear to be in aveilut.
The Tosafot ha-Rosh argues that Yehezkel is certainly not being commanded to behave in a manner that is more stringent than others. Thus, if he could not speak, we can conclude that other mourners cannot, either.