What is said about the knife

Narrated Umaiya Ad-Damri:

I saw the Prophet eating of a shoulder (of a sheep) by cutting from it and then he was called to prayer and he prayed without repeating his ablution.

Narrated Az-Zuhri:

as above and added that the Prophet put the knife down.

حَدَّثَنَا عَبْدُ الْعَزِيزِ بْنُ عَبْدِ اللَّهِ، قَالَ حَدَّثَنِي إِبْرَاهِيمُ بْنُ سَعْدٍ، عَنِ ابْنِ شِهَابٍ، عَنْ جَعْفَرِ بْنِ عَمْرِو بْنِ أُمَيَّةَ، عَنْ أَبِيهِ، قَالَ رَأَيْتُ النَّبِيَّ ﷺ يَأْكُلُ مِنْ كَتِفٍ يَحْتَزُّ مِنْهَا، ثُمَّ دُعِيَ إِلَى الصَّلاَةِ فَصَلَّى وَلَمْ يَتَوَضَّأْ. حَدَّثَنَا أَبُو الْيَمَانِ أَخْبَرَنَا شُعَيْبٌ عَنِ الزُّهْرِيِّ وَزَادَ فَأَلْقَى السِّكِّينَ.