Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) says that the Messenger of Allah (peace and blessings be upon him) commanded Amr bin Hazm regarding sadaqat al-fitr that "it should be given as half a sa' of wheat or a sa' of dates."
This is not sound. How could it be sound, when the narration of the group (of narrators) from Nafi', from Ibn Umar, is that equating the sa' with two mudds of wheat happened after the Messenger of Allah (peace and blessings be upon him)?
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الزكاة / 7711