'So,' he said, as he rocked gently from side to side, 'you may as well tell me. Why 71–hour Ahmed?'
'He killed a man,' said Jabbar.
'And D'regs object to a little thing like that?'
'In the man's own tent! When he had been his guest for nearly three days! If he had but waited an hour–'
'Oh, I see. Definitely bad manners. Had the man done anything to deserve it?'
'Nothing! Although...'
'Yes?'
'The man had killed El-Ysa.' The D'reg's tone suggested that this wasn't much of a mitigating circumstance, but that it ought to be mentioned out of completeness.
'Who was she?'
'El-Ysa was a village. He poisoned a well. There had been a dispute over religion,' he added. 'One thing led to another... but even so, to break the tradition of hospitality... '
'Yes, I can see that's a terrible thing. Almost... impolite.'
'The hour was important. Some things should not be done.'

From Jingo by Sir Terry Pratchett