Not graded
Companion’s words (mawquf) Musnad Ahmad 518
حَدَّثَنَا عَبْدُ الرَّزَّاقِ حَدَّثَنَا مَعْمَرٌ عَنْ قَتَادَةَ قَالَ صَلَّى الزُّبَيْرُ عَلَى عُثْمَانَ رَضِيَ اللَّهُ عَنْهُ وَدَفَنَهُ وَكَانَ أَوْصَى إِلَيْهِ
This hadith has no English translation yet: the Arabic text, the reference and the grade are shown here.
Reported by Ahmad (No. 518).