Arthashastra
एक अयने वा शैल स्तम्भ वाट खञ्जन अन्तर् उदके वा स्व भूमि बलेन अभिहन्युः ॥
Or occupying an advantageous position, they may slay the enemy when he is marching in a narrow path passable by a single man, or on a mountain, or near the trunk of a tree, or under the branches of a banian tree, or in water.
english translation
eka ayane vA zaila stambha vATa khaJjana antar udake vA sva bhUmi balena abhihanyuH ॥
hk transliteration by Sanscript