2 Samuel 17:17-18

171Now Jonathan and Ahimaaz were staying at 2En-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.

18But a boy did see them, and he told Absalom; so the two of them left quickly and came to the house of a man 3in Bahurim, who had a well in his courtyard, and they went down 4into it.