פירוש על עבודה זרה 14:10

There seems to be another sage who holds the same opinion as Nahum the Mede. Ben Batera also allows selling a horse. But when we look deeper, we will see that they do not hold the same opinion. Ben Batera allows one to sell any horse to an idolater. This is because a horse’s work is to carry a rider, and carrying a rider is not considered work. But the other sages still prohibit selling horses, less one come to sell an ox, which pulls a plow. Nahum the Mede does not allow any horse, just old male horses. Thus he must hold like the other rabbis, and the other rabbis say that Nahum the Mede’s leniency should be hidden.