We are all one man's sons - We do not belong to different tribes, and it is not likely that one family would make a hostile attempt upon a whole kingdom. This seems to be the very ground that Joseph took, viz., that they were persons belonging to different tribes. Against this particularly they set up their defense, asserting that they all belonged to one family; and it is on the proof of this that Joseph puts them, Genesis 42:15, in obliging them to leave one as a hostage, and insisting on their bringing their remaining brother; so that he took exactly the same precautions to detect them as if he had had no acquaintance with them, and had every reason to be suspicious.

We are all one man's sons,.... Therefore not likely to be spies; it could hardly be thought that a single family should engage in such an affair; or that one man would, send his sons as spies, and especially all of them, it being a dangerous affair, and they being liable to be taken up and put to death; and as more families than one must be concerned in such an enterprise, it is reasonable to suppose, that if they had been spies they would have been of different families, and also not together, but in different parts of the kingdom, to observe the fittest place to enter in at and execute their design:
we are true men: that spoke truth when they said they came to buy corn; were honest, upright, and sincere in what they said, nor would they, nor durst they, tell a lie:
thy servants are no spies; this they expressed in the strongest terms, and with the fullest assurance they could, detesting the charge and character of being spies.