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

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