Jamieson, Fausset and Brown on Genesis 44:6-7

6-7. he overtook them, and he spake ... these words--The steward's words must have come upon them like a thunderbolt, and one of their most predominant feelings must have been the humiliating and galling sense of being made so often objects of suspicion. Protesting their innocence, they invited a search. The challenge was accepted [Ge 44:10, 11]. Beginning with the eldest, every sack was examined, and the cup being found in Benjamin's [Ge 44:12], they all returned in an indescribable agony of mind to the house of the governor [Ge 44:13], throwing themselves at his feet [Ge 44:14], with the remarkable confession, "God hath found out the iniquity of thy servants" [Ge 44:16].