It was narrated from Abu Sa'eed Al'Khudri and Abu Hurairah that:
the Messenger of Allah appointed a man in charge of kharibar and he brought some Janib dates. The messenger of Allah said; "Are all the dates if khaibar like this?" He said: "No (by Allah, O Messenger of Allah) we take a Sa of these for two for three Sas (of other types of dates)." The messenger of Allah said: "do not do that Sell the mixed dates for Dirhams then buy the Janib dates with the Dirhams" ,"