אֶֽעֱבֹ֨ר בְּכָל־צֹֽאנְךָ֜ הַיּ֗וֹם הָסֵ֨ר מִשָּׁ֜ם כָּל־שֶׂ֣ה ׀ נָקֹ֣ד וְטָל֗וּא וְכָל־שֶׂה־חוּם֙ בַּכְּשָׂבִ֔ים וְטָל֥וּא וְנָקֹ֖ד בָּעִזִּ֑ים וְהָיָ֖ה שְׂכָרִֽי׃
«今天我要走遍你的羊群，你要把其中凡有點的、有斑的羊，綿羊中凡紅棕色的，以及山羊中凡有斑的、有點的，都挑出來；日後生下這樣的，就作我的工價。»
Mishnah Bava Batra
There are four rules with regards to those who sell:If one has sold good wheat and it turns out to be bad, the buyer can retract. If he sold bad wheat and it is found to be good, the seller can retract. [But if one sold] bad wheat and it is found to be bad, or good wheat and it is found to be good, neither may retract. [If one has sold] dark wheat and it turned out to be white; Or white and it turned out to be dark; Or [if he sold] olive wood and it turned out to be sycamore wood; Or sycamore wood and it turned out to be olive wood; Or [if he sold] wine and it turned out to be vinegar; Or vinegar and it turned out to be wine; Either of them may retract.