Jamieson, Fausset and Brown on 1 Samuel 26:4-5

4-5. David ... sent out spies ... and David arose, and came to the place where Saul had pitched--Having obtained certain information of the locality, he seems, accompanied by his nephew (1Sa 26:6), to have hid himself, perhaps disguised, in a neighboring wood, or hill, on the skirts of the royal camp towards night, and waited to approach it under covert of the darkness.

1Sa 26:5-25. David Stays Abishai from Killing Saul, but Takes His Spear and Cruse.