The Peak of Eloquence · Hadith 1509 (#Passage #318)

وَاجْعَلْ لِرَأْسِ كُلِّ أَمْرٍ مِنْ أُمُورِكَ رَأْساً مِنْهُمْ، لَا يَقْهَرُهُ كَبِيرُهَا، وَلَا يَتَشَتَّتُ عَلَيْهِ كَثِيرُهَا، وَمَهْمَا كَانَ فِي كُتَّابِكَ مِنْ عَيْبٍ فَتَغَابَيْتَ عَنْه أُلْزِمْتَهُ.

Establish one chief for every department of work. He should not be incapable of big matters, and a rush of work should not perplex him. Whenever there is a defect in your secretaries which you overlook, then you will be held responsible for it.

Gradings are classical jarḥ-wa-taʿdīl, name-matched to a rijāl index (not individually re-verified).