Sayyidah Zaynab (may Allah be pleased with her) said: The Messenger of Allah (peace and blessings be upon him) gave me 50 wasqs of dates at Khaybar and 20 wasqs of barley. Asim bin Adi (may Allah be pleased with him) came to me and said: "Shall I give you, here in Madinah, the measure of your property at Khaybar in exchange for it?" I said: "Let me ask first." Then I mentioned it to Sayyiduna Umar bin al-Khattab (may Allah be pleased with him), and he said: "Do not do it, for who will stand as guarantor between the two of you?"
(b) In the narration of Ibn Abd al-Wahhab: Asim came to me during the caliphate of Sayyiduna Umar (may Allah be pleased with him).
Hadith Referenceالسنن الكبرى للبيهقي / كتاب البيوع / 10945
Ata bin Abi Rabah (may Allah have mercy on him) said that Sayyiduna Abdullah bin al-Zubayr (may Allah be pleased with him) used to take money from people in Makkah, then write for it to Mus'ab bin al-Zubayr in Iraq, and they would collect it from him. Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) was asked about this, and he too saw no harm in it. It was said to him: What if they take more than that? He said: There is no harm, as long as they take the weight of their dirhams.
(b) This was also narrated from Sayyiduna Ali (may Allah be pleased with him); if it is authentic from him and from Sayyiduna Ibn Abbas (may Allah be pleased with them both), then what is meant, and Allah knows best, is when it is without a condition.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب البيوع / 10947