Mishkat al-Masabih 21 Foods كتاب الأطعمة 27

وَعَنِ ابْنِ عُمَرَ قَالَ: نَهَى رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ أَنْ يَقْرِنَ الرَّجُلُ بَيْنَ التَّمْرَتَيْنِ حَتَّى يستأذِنَ أَصْحَابه

Ibn ‘Umar said God’s messenger prohibited anyone taking two dates together before asking permission from his companions. (Bukhari and Muslim.)