Musannaf Ibn Abi Shaybah

Hazrat Yahya bin Abi Kathir narrates that Hazrat Umar (may Allah be pleased with him) sent his servant with one sa’ of dates and instructed him to bring back one sa’ of barley in exchange. He strictly forbade him from taking more than one sa’.

Hazrat Abu Abdur Rahman considered it undesirable that two qafiz of barley be taken in exchange for one qafiz of wheat.

Hazrat Sulaiman bin Yasar narrates that the slave of Hazrat Abdur Rahman bin Aswad bin Abd Yaghuth came to him and informed him that his barley had finished. He instructed him to take wheat and buy barley in exchange for it, and told him to take it in equal measure and not to take more. Hazrat Sulaiman bin Yasar has narrated similarly about Hazrat Sa’d bin Abi Waqqas (may Allah be pleased with him) as well.