Shama-il Tirmidhi Chapter 038, Hadith Number 004 (245).

Ibn 'Abbaas Radiyallahu 'Anhu reports: "Once Rasulullah Sallallahu 'Alayhi Wasallam slept and began snoring. It was, the nature of Rasulullah Sallallahu 'Alayhi Wasallam that he snored, when he slept. Bilaal Radiyallahu 'Anhu gave the call to prepare for salaah. Rasulullah Sallallahu 'Alayhi Wasallam awakened and performed the salaah. He did not perform the wudu". This hadith has a detailed incident.

Commentary
It is a peculiarity of the Ambiyaa that their wudu does not become invalid by sleeping. For this reason Sayyidina Rasulullah Sallallahu 'Alayhi Wasallam did not perform wudu. Sayyidina Rasulullah Sallallahu 'Alayhi Wasallam informed us of the reason. When the Ambiyaa sleep their hearts and minds do not sleep, only their eyes sleep. The dreams of the Ambiyaa are also revelations. They are protected from the influence of the shaytaan. The incident that Imaam Tirmidhi refers to took place at the House of the aunt of Sayyidina ibn 'Abbaas Radiyallahu 'Anhu. It will be discussed in the fifth hadith of the ensuing chapter. The subject was not relevant to this chapter, therefore the author omitted it here.