(Mishnah): If a seller said that he is selling the land and "measuring with a rope; whether it is small or large'' (which are contradictory, since measuring with a rope implies that he will be very accurate), the latter phrase cancels the former.

If he said, "Whether it is small or large, measuring with a rope'', the first clause cancels the second, which is the view of Ben Nanas.

If he sold (a Beis Kur) and showed him the borders of the land, if he gives him less than a sixth smaller than shown, the sale is valid; if it is actually a sixth smaller than shown, the seller must reduce the payment accordingly.

(Gemara) - R. Chiya (Beraisa): One who sells a slave to his friend and the slave is discovered to be a thief or a kidnapper, the sell is valid.

But if he is discovered to be an armed bandit or he has been commandeered for the king's work, the sale is invalid.

If he gave him exactly a sixth smaller than he had shown, he must also reduce the payment (not only if it was more than a sixth).