Now therefore send quickly Lest Absalom's and the people's minds change, and Ahithophel persuade them to pursue you speedily. Jonathan and Ahimaaz stayed by En-rogel Or the fuller's fountain. Being to carry the intelligence, they had not returned into the city, but found some pretence for tarrying without the walls at this place, probably that they might wash and cleanse themselves from some legal pollution. Indeed, it would have been difficult, if not impossible, to have sent them out of the city without their being discovered. A wench went and told them Being sent by Zadok, and pretending, perhaps, to go thither for water, or to wash some clothes. And they went and told King David After a little stop in their way, as is here related.
Related Commentaries of 2 Samuel 17:16
2 Samuel 17:16-17
16 Now therefore send quickly, and tell David, saying, Lodge not this night in the plains of the wilderness, but speedily pass over; lest the king be swallowed up, and all the people that are with him.
17 Now Jonathan and Ahimaaz stayed by Enrogel; for they might not be seen to come into the city: and a wench went and told them; and they went and told king David.