‘And Israel said, “Why did you treat me so badly as to tell the Man whether you had yet a brother?” And they said, “The Man asked us firmly (literally - ‘asked us asking') about ourselves and about our relatives, saying, ‘Is your father yet alive? Have you a brother?' And we told him according to the tenor of these words. Could we possibly have known that he would say, ‘Bring your brother down'?”
In his grief and fear Jacob is being quite unreasonable. They had had no reason to withhold the information and they knew that to have given even a hint of deceit would have been their downfall. The only significance they had seen in the close questioning was the suspicion that they were spies.
“They said” - now the other brothers are joining in. They are all agreed that they cannot face the Man without having Benjamin with them. They would immediately be killed as spies.