Jabalah bin Suhaym said: We were with Sayyiduna Abdullah bin al-Zubayr (may Allah be pleased with them both) in a year of famine, and we were given dates. Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) passed by us and said: "Do not eat them two at a time, for the Messenger of Allah (peace and blessings be upon him) forbade this, unless the companion gives permission." Shu'bah (may Allah have mercy on him) said: "Al-idhn" (the permission) is the saying of Sayyiduna Abdullah bin Umar (may Allah be pleased with them both).
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصداق / 14633