Yadayim ידיים

The sages ruled that hands are reckoned impure of themselves, and established washing from a vessel. The tractate works out which vessel is fit, how much water is needed, what invalidates the washing.

Strangely, that same impurity of hands became the measure of a book's holiness: sacred books "render the hands impure", ordinary ones do not. And so it is precisely here that the debate is recorded over whether the Song of Songs and Ecclesiastes are holy, and Rabbi Akiva's answer: the whole world is not worth the day the Song of Songs was given, for all the Writings are holy, but the Song of Songs is the holy of holies.

Order: Tohorot. There is no Gemara in either Talmud—the tractate remained mishnah.