6. Ali ibn Ibrahim has narrated from his father from Ibn Abi ‘Umayr from Hammad from al-Halabiy who has said the following: “About the case of a man who asks another man to sell the fruits of his certain palm tree for two Qafiz (a certain unit of measurement) of dates or less or more that he names as he likes, abu ‘Abd Allah , has said, ‘It is not harmful.’ He (the Imam) then said, ‘Fresh dates and half-ripe dates from one palm tree can be exchanged and it is not harmful but mixing of old dates and half-ripe dates is not valid and so also is the case of raisin and grape.’”