Jabala bin Suhaim said: We were in Medina when we faced a year of famine. At that time, Abdullah bin Zubair (may Allah be pleased with him) used to give us dates (as rations). When Abdullah bin Umar (may Allah be pleased with them both) would pass by us, he would say: Do not eat two dates together, because the Messenger of Allah (peace and blessings be upon him) forbade eating two dates together except with the permission of the one sitting with you.
Hadith Referenceسنن دارمي / من كتاب الاطعمة / 2096
Hadith Takhrijاس روایت کی سند صحیح اور حدیث متفق علیہ ہے۔ دیکھئے: [بخاري 2455، 5446] ، [مسلم 2045] ، [أبوداؤد 3834] ، [ترمذي 1814] ، [ابن ماجه 3331] ، [أبويعلی 5736]
Brief Explanation
(Commentary on Hadith 2095)
From this hadith, it is understood that eating two dates at once is prohibited, and this prohibition applies when others are also eating together, because it is against etiquette and inappropriate, and it involves depriving others of their right. However, if the other people also eat two dates at once, or if they grant permission, then there is no harm.
Some scholars have declared eating two dates at once to be haram (forbidden), and some have considered it makruh (disliked).