Q: What is Roohul Qudus?
A: Roohul-Qudus, according to the majority of Mufassireen (commenators of the Holy Quran) refers to Jibreel (alayhis-salaam). Allama Ibni Katheer has discussed this in detail under verse 87 of Surah Baqarah and confirms that Roohul-Qudus is Jibreel alayhis-salaam (Tafseer Ibn Katheer vol.1 p. 321)
In Bukhari and Abu Dawood there appears a hadith in which Rasoolullah (sallallahu alayhi wasallam) asked Allah Ta’ala to strenghthen Hassaan bin Thaabit (radhiyallahu anhu) with the Roohul-Qudus. This too, meant Jibreel (alayhis-salaam).
And Allah Ta’ala knows best
Mufti Siraj Desai