Reference for Bava Metzia 157:1
דברי ר"ש בן אלעזר שהיה ר"ש בן אלעזר אומר אם בדרך הילוכה ניטלה אומר לו הרי שלך לפניך ואם לא חייב להעמיד לו חמור
This is the view of R. Simeon b. Eleazar; for he used to maintain: If it was taken on the route of its journey, he can say to him, 'Here is yours before you;' if not, he is bound to replace it. But can you possibly assign it [all] to R. Simeon b. Eleazar? Surely, the first clause states, 'If one hires an ass, and it is struck by lightning or turns rabid, he [the owner] can say to him, "Here is yours before you:"' whereas R. Simeon b. Eleazar ruled: If one hires an ass to ride upon it, and it is struck by lightning or turns rabid, he [the owner] must furnish him with another! — Said Rabbah son of R. Huna: If for riding, the case is different.<span class="x" onmousemove="('comment',' A blind or rabid animal is fit to carry burdens, but not to be ridden upon. ');"><sup>1</sup></span>