I couldn’t find the exact quote I was thinking of, but the following from the beginning of Chapter XXX gives something of an idea:

Fakhri Pasha was still playing our game. He held an entrenched line around Medina, just far enough out to make it impossible for the Arabs to shell the city. (Such an attempt was never made or imagined. ) The other troops were being distributed along the railway, in strong garrisons at all water stations between Medina and Tebuk, and in smaller posts between these garrisons, so that daily patrols might guarantee the track. In short, he had fallen back on as stupid a defensive as could be conceived. Garland had gone south-east from Wejh, and Newcombe north-east, to pick holes in it with high explosives. They would cut rails and bridges, and place automatic mines for running trains.

http://gutenberg.net.au/ebooks01/0100111.txt
http://etext.library.adelaide.edu.au/l/lawrence/te/seven/