1 Samuel 26:5

And David arose, and came to the place where Saul had pitched,
&c.] Came near it, within sight of it; so that he could take a view of it with his naked eye, and observe where and in what manner he was encamped:

and David beheld the place where Saul lay, and Abner the son of Ner,
the captain of his host;
where he and his general had their quarters in the camp:

and Saul lay in the trench;
or circuit; not in the foss or ditch thrown up, in which an army sometimes lies entrenched; but this is to be understood either of the camp itself, so called, as Ben Gersom, Abarbinel, and Ben Melech think, because it lay in a circular form, that all comers to it on every side might be seen; or else a sort of fortress all around the camp, made of carriages joined together; and as the word signifies a carriage, cart or chariot, it may design the chariot in which Saul slept, as kings have been used to do when not in their houses; and to this the Septuagint agrees, which uses a word that Procopius Gazaeus says signifies one kind of a chariot, and is used of a chariot drawn by mules, in the Greek version of ( Isaiah 66:20 ) ; Grotius observes, kings used to sleep in chariots where there were no houses; (See Gill on 1 Samuel 17:20); though he rather seems to have slept, "sub die", in the open air:

and the people pitched round about him;
both for the sake of honour, and for his greater security; this shows it could not be the loss he laid in, for then they could not pitch around him.