If their dispute is over the length of the journey:
• Should it arise before the passenger mounts, or after only a brief period in the saddle, each party must swear an oath and the contract is cancelled.
• If it arises after a long stretch has been travelled, or once the distance claimed by the owner of the animal has been reached, the owner’s word with respect to that distance is accepted—provided the hire contract is already binding and what he asserts is plausible.
• If the contract has not yet become binding yet his claim is plausible, the two parties swear oaths, the hire is rescinded on the basis of the greater of the two alleged distances, and the owner is awarded whatever share of the fare corresponds to the distance he claims. The same ruling applies where the contract is binding but his statement is implausible.

If they agree on the distance yet disagree over the fare, the lessee’s statement prevails, whether or not he has already paid, because the claim lies against him.

If they differ over both the distance and the fare—as when the owner, while in Córdoba, says, “You hired my mount to go to Carmona for two dinars,” and the lessee replies, “Rather, for one dinar to Seville”—then:
• If the dispute occurs before mounting, or after so little travel that returning causes no harm, they swear oaths and the contract is annulled.
• If it occurs after extensive travel or after reaching the distance claimed by the owner:
– When the lessee has not yet paid anything, the owner’s word is accepted regarding the distance, and the lessee’s word regarding the fare. The lessee must pay whatever would be due for the stretch from Córdoba to Carmona, calculated at the rate that would have applied had the hire been to Seville, for that is the lessee’s assertion. If the owner’s claim is implausible, the lessee is liable for two dinars.
– When the lessee has already paid the fare he claims was for the longer journey and the owner’s account appears plausible, the owner’s word prevails as to the distance. The owner keeps the payment he has received and need not refund any of it, for the claim against him concerns only part of that amount. He may say, “It is mine—and more besides,” and his word is accepted regarding what is already in his hand, though not concerning any further increase. The obligation for the remainder of the journey drops away from him, whether his statement is plausible or not—unless it is implausible. In that case, the fare acknowledged by the lessee is divided across the whole journey, and the owner receives the portion proportionate to the distance he alleges.

This much suffices for the discussion of this issue.