2 Samuel 17:18-22

But a boy did see them, and he told Absalom; so the two of them left quickly and came to the house of a man in Bahurim, who had a well in his courtyard, and they went down into it.

And the woman took a cover and spread it over the well’s mouth and scattered barley meal on it, so that nothing was known.

Then Absalom’s servants came to the woman at the house and said, “Where are Ahimaaz and Jonathan?” And the woman said to them, “They have crossed the brook of water.” And when they searched and did not find them, they returned to Jerusalem.

It came about after they had departed, that they came up out of the well and went and reported to King David; and they said to David, “Set out and cross over the water quickly, because this is what Ahithophel has advised against you.”

Then David and all the people who were with him set out and crossed the Jordan; by dawn not even one remained who had not crossed the Jordan.