8. Muhammad ibn Yahya and others have narrated from Muhammad Ahmad from Ayyub ibn Nuh from al-‘ Abbas ibn ‘Amir from Dawud ibn al-Husayn from Mansur who has said the following
“I once asked him (the Imam) (a.s.), about exchange of one sheep for two sheep, one egg for two eggs. He (the Imam) said, ’It is not harmful as long as it is not in measures and weighing.’”