ध्रुवं हि साक्षिभिः श्रोतव्यम् ॥ कZ_०३.११.४८ ॥
dhruvaṃ hi sākṣibhiḥ śrotavyam
Witnesses must be heard with certainty and decisiveness (i.e., their testimony must be properly taken and fixed).
That testimony should be taken in a firm, definite, properly fixed manner—reducing ambiguity and later dispute.