What Has Been Related About The Bai'ah (Pledge of Allegiance) Sunan Abi Dawud 2942

Arabic hadith text
حَدَّثَنَا عُبَيْدُ اللَّهِ بْنُ عُمَرَ بْنِ مَيْسَرَةَ، حَدَّثَنَا عَبْدُ اللَّهِ بْنُ يَزِيدَ، حَدَّثَنَا سَعِيدُ بْنُ أَبِي أَيُّوبَ، حَدَّثَنِي أَبُو عَقِيلٍ، زُهْرَةُ بْنُ مَعْبَدٍ عَنْ جَدِّهِ عَبْدِ اللَّهِ بْنِ هِشَامٍ، قَالَ وَكَانَ قَدْ أَدْرَكَ النَّبِيَّ صلى الله عليه وسلم وَذَهَبَتْ بِهِ أُمُّهُ زَيْنَبُ بِنْتُ حُمَيْدٍ إِلَى رَسُولِ اللَّهِ صلى الله عليه وسلم فَقَالَتْ يَا رَسُولَ اللَّهِ بَايِعْهُ ‏.‏ فَقَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏"‏هُوَ صَغِيرٌ ‏"‏ ‏.‏ فَمَسَحَ رَأْسَهُ ‏.‏
Translation
Narrated 'Abd Alla b. Hisham,

who had lived during the time of the Prophet (ﷺ), and his mother, Zaynab bint Humayd, took him to the Messenger of Allah (ﷺ) and said, "O Messenger of Allah, accept his oath of allegiance." The Messenger of Allah (ﷺ) said, "He is young." Then he wiped over his head.