諸經要集 5.86

5.86

又五分律云。若月直監食人。欲知生熟醎酢。得貯掌中舌舐甞之（齋法經不許口甞者為無好心貪心甞故犯罪）。

Also, the Mahīśāsaka-vinaya states: "If the duty-monk overseeing the food wishes to know whether it is raw or cooked, salty or sour, he may hold it in his palm and lick it with his tongue to taste it. (The Zhaifa jing does not allow tasting it with the mouth because doing so without good intentions but out of craving constitutes an offense.)"