Seven Pillars of Wisdom by T.E. Lawrence

Mifleh was past tears, thinking I had intentionally let the train through; and when the Serahin had been told the real cause they said 'Bad luck is with us'. Historically they were right; but they meant it for a prophecy, so I made sarcastic reference to their courage at the bridge the week before, hinting that it might be a tribal preference to sit on camel-guard. At once there was uproar, the Serahin attacking me furiously, the Beni Sakhr defending. Ali heard the trouble, and came running.

When we had made it up the original despondency was half forgotten. Ali backed me nobly, though the wretched boy was blue with cold and shivering in an attack of fever. He gasped that their ancestor the Prophet had given to Sherifs the faculty of 'sight', and by it he knew that our luck was turning. This was comfort for them: my first instalment of good fortune came when in the wet, without other tool than my dagger, I got the box of the exploder open and persuaded its electrical gear to work properly once more.