Exchange of One Kind of Food Items for another Kind

7. Ahmad ibn Muhammad has narrated from al-Hassan ibn Mahbub from Sayf al-Tammar who has said the following: “I once asked abu Basir to ask abu ‘ Abd Allah عليه السلام, about the case of a man who exchanges two baskets of fresh half-ripe dates for one basket of Mushaqaq (stone-free) dates. Abu Basir asked him (the Imam) and he (the Imam) said, ‘It is Makruh (detestable).’ Abu Basir then asked, ‘Why it is Makruh (detestable)?’ He (the Imam) said, ‘Ali ibn abu Talib عليه السلام, disliked to exchange one wasaq of dates of al-Madinah for two wasaq (a certain unit of measurement) of dates of Khaybar because dates of al-Madinah are of inferior quality and Ali عليه السلام, would not dislike lawful things.’”