Musannaf Ibn Abi Shaybah

It is narrated from Ibrahim that the Companions used to prefer that the zakat of each thing be given from that very thing: zakat of silver from silver, zakat of gold from gold, zakat of cows from cows, and zakat of goats from goats.

Hasan disliked that goods be taken as zakat.

Hazrat Ibn Jurayj states that I heard from Hazrat Ibn Abi Najih, who says that Hazrat Umar bin Abdul Aziz wrote regarding the zakat of dates: The zakat of Barni dates (a special type of date) should be paid from Barni dates, and the zakat of Lawn dates (a special type of date) should be paid from the same dates. Barni dates will not be collected for the zakat of Lawn dates.