Sahih Bukhari Volume 3, Book 47, Hadith Number 749.

Narated By Said bin Jubair : Ibn Abbas said: Um Hufaid, Ibn ‘Abbas’s aunt sent some dried yogurt (butter free), ghee (butter) and a mastigar to the Prophet as a gift. The Prophet ate the dried yogurt and butter but left the mastigar because he disliked it. Ibn ‘Abbas said, “The mastigar was eaten at the table of Allah’s Apostle and if it had been illegal to eat, it could not have been eaten at the table of Allah’s Apostle.”