Not graded
Companion’s words (mawquf) Musnad Ahmad 490
حَدَّثَنَا عَبْد اللَّهِ حَدَّثَنَا شَيْبَانُ بْنُ أَبِي شَيْبَةَ حَدَّثَنَا مُبَارَكُ بْنُ فَضَالَةَ حَدَّثَنَا الْحَسَنُ قَالَ شَهِدْتُ عُثْمَانَ يَأْمُرُ فِي خُطْبَتِهِ بِقَتْلِ الْكِلَابِ وَذَبْحِ الْحَمَامِ
This hadith has no English translation yet: the Arabic text, the reference and the grade are shown here.
Reported by Ahmad (No. 490).