Genesis 43:18
And the men were afraid, because they were brought into Joseph’s house; and they said, Because of the money that was returned in our sacks at the first time are we brought in; that he may seek occasion against us, and fall upon us, and take us for bondmen, and our asses.
The men were seized with fear when they were brought into Joseph's house, the house of the ruler, to dine with him. What was in fact an act of hospitality they mistook for a trap laid for them. They said among themselves that it was because of the money that had been returned and found in their sacks on the first journey that they were now being brought in, to be called to account for it.
They suspected that the money had been placed there on purpose, planted in the sacks in order to seek and find occasion against them. They expected that money to be used as a pretext to accuse them and to fall upon them and take them for bondmen and slaves. They feared also that their donkeys and asses would be seized with them. They thought they had been brought inside the house so that this seizure could be carried out more easily.
Though they were innocent, they feared punishment as thieves and captives. Their dread grew out of suspicion toward the ruler who had treated them roughly before, joined with uncertainty about why the money had been returned to them.