Genesis 43:7
And they said, The man asked us straitly of our state, and of our kindred, saying, Is your father yet alive? have ye another brother? and we told him according to the tenor of these words: could we certainly know that he would say, Bring your brother down?
The words are the brothers' explanation to Jacob for why they had told the Egyptian ruler about their family. Their account is that the man questioned them closely about their circumstances and their relatives. That close questioning asked whether their father was still alive and whether they had another brother.
They had answered his questions about their family truthfully, just as the questions were put to them. They could not have known beforehand that he would then require them to bring Benjamin down to Egypt. Judah speaks these words when want presses for food and Jacob tells his sons to go again to Egypt.
The man had solemnly warned them that they would not see his face unless their brother was with them. Benjamin's going is therefore the necessary condition for returning, and they are unable to buy more grain unless Jacob sends him. Lingering over Jacob's unwillingness to send Benjamin has already delayed a journey to Egypt and back.