It has been narrated on the authority of Ibn 'Umar that the Messenger of Allah (may peace be upon him) said: When Allah will gather together, on the Day of Judgment, all the earlier and later generations of mankind, a flag will be raised (to mark off) every person guilty of breach of faith, and it will be announced that this is the perfidy of so and so, son of so and so (to attract the attention of people to his guilt).