‘And Judah said, “What shall we say to my lord? What words can we use? Or how shall we clear ourselves? God has found out the iniquity of your servants. Behold, we are my lord's bondmen, both we and also he in whose sack the cup was found.”
Judah speaks up for them all. On their behalf he accepts that they have no argument. The cup has been found. There is little point in arguing innocence.
“God has found out the iniquity of your servants.” This is not so much an admission of guilt as a surrender to the past. It is probable that he has in mind what they had done to their long lost brother. He recognises that they are now being punished for that. The impossible circumstance in which they now find themselves can only be due to God's long arm which has reached out into the future to punish them. He has found them out. Whatever the circumstance as regards the cup they are not innocent, as they all know. So they accept the inevitable.
It is noteworthy that they do not refer back to the steward's promise that only the guilty one should be accountable (Genesis 44:10). They accept their collective guilt and do not dream of going back without Benjamin. Besides the steward may not have been speaking for his lord and this is no time for arguing fine points before this great lord. And the fact is that they have just given up.