What is the ruling on a mentally ill person not performing the Farewell Tawaf? And what is the expiation for it?

Scholars have differed concerning the ruling on theing Farewell Tawaf for a pilgrim who is not from Mecca. The majority of scholars view it as obligatory, citing the Hadith from Ibn Abbas: "The people were commanded that their last rite with the House should be Tawaf, except that it was lightened for the menstruating woman." As for the Malikis, they consider it Sunnah (recommended). The first opinion is more cautious, and according to it, whoever omits it must offer a sacrifice (a sheep or one-seventh of a camel, to be slaughtered and distributed among the poor of the Haram). If one cannot find an animal, then one must fast for ten days. As for omitting it in 'Umrah, there is no penalty, as it is considered Sunnah by the majority of scholars.