It was narrated from Sa’d, the freed slave of Abu Bakr – and Sa’d used to serve the Messenger of Allah ﷺ and he liked this Hadith – that the Prophet ﷺ forbade eating two dates at once.
عَنْ سَعْدٍ مَوْلَى أَبِي بَكْرٍ وَكَانَ سَعْدٌ يَخْدُمُ النَّبِيَّ ﷺ وَكَانَ يُعْجِبُهُ حَدِيثُهُ أَنَّ النَّبِيَّ ﷺ نَهَى عَنِ الإِقْرَانِ يَعْنِي فِي التَّمْرِ