2 Samuel 17:15-19

Then Hushai said to Zadok and to Abiathar the priests, “This is what Ahithophel advised Absalom and the elders of Israel to do, and this is what I have advised.

Now then, send a messenger quickly and tell David, saying, ‘Do not spend the night at the river crossing places of the wilderness, but by all means cross over, or else the king and all the people who are with him will be destroyed.’ ”

Now Jonathan and Ahimaaz were staying at En-rogel, and a female servant would go and inform them, and they would go and inform King David, for they could not allow themselves to be seen entering the city.

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.