The verb bahiya yabhā, verbal noun bahā’, is said of a tent when it rips and become useless. Active participle bāhin describes a tent that is ill furnished. The transitive verb abhā, formed on the same root, means to rip something up—as heard in the saying: Al-mi‘zā tubhī wa-lā tubnī (Tents are unmade by goats, not made). This is because goats climb on top of tents, and rip their fabrics, and as the rents in them grow wider, the tent becomes unfit for habitation.
Conveyed along with this is the idea that goat hair is not suitable for spinning, and this is why tents are not made of their hairs, but from camel hair and sheep's wool. Abū Zayd said: "The meaning of lā tubnī in the saying is that tents are not fabricated from goat's wool. If this were possible, then tents would [in a metonymical sense] be 'made by' goats."
In Rectifying the Errors of Abū ‘Ubayd, Ibn Qutayba says: "In many places I have seen well-pitched Arab tents of goat hair." And then he said: "The meaning of lā tubnī in the saying is that goats are no good for a tent's roof (binā’)."
Al-Azharī says: "The Bedouin have two kinds of goat. One is hairless, like the goats of the Hijaz and the lowlands [of the Tihama region], and goats such as are pastured in the uplands [of Central Arabia], far from arable terrain. The other kind of goat has long hair [suitable for spinning and weaving], and arable lands are its terrain, as it roams the outskirts of settled areas where water-sources are plentiful, like the goatkind of the Kurds in the mountains, and in the territories of Khorasan.
"The saying 'Tents are unmade by goats, not made' would seem to be local to nomads of West Arabia and the Central Arabian plateau. Abū Zayd is correct in what he said."
Ibn Manẓūr, The Tongue of the Arabs, art. √bhw