शौचाशौचममात्यानां राजा मार्गेत सत्त्रिभिः ॥ कZ_०१.१०.२०च्द् ॥
śaucāśaucam amātyānāṃ rājā mārgeta sattribhiḥ
The king should ascertain the purity or impurity (integrity or corruption) of ministers by means of secret agents (sattra/sattrin).
Open inquiries trigger concealment and collusion; covert verification yields more truthful behavioral evidence and protects the king from manipulated reporting.