The Peak of Eloquence · Hadith 1502 (#Passage #311)

ثُمَّ تَفَقَّدْ أَعْمَالَهُمْ، وَابْعَثِ الْعُيُونَ مِنْ أَهْلِ الصِّدْقِ وَالوَفَاءِ عَلَيْهِمْ، فَإِنَّ تَعَاهُدَكَ فِي السِّرِّ لِأُمُورِهِمْ حَدْوَةٌ لَهُمْ عَلَى اسْتِعْمَالِ الْأَمَانَةِ، وَالرِّفْقِ بِالرَّعِيَّةِ.

You should also check their activities and have people who report on them who should be truthful and faithful, because your watching their actions secretly will urge them to preserve trust with and to be kind to the people.

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