Assalaamu alaykum. How authentic is it that there is a Hoori (maiden of Paradise) in Paradise that is so beautiful that the people would die if they were to look at her beauty?

All perfect praise be to Allah, The Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.

Perhaps you are referring to what Ibn Al-Qayyim mentioned in his book Haadi Al-Arwaah, that ‘Ataa' As-Sulami said to Maalik ibn Deenaar, "O Abu Yahya, (tell us something that would) make us yearn for Paradise." Maalik said, "There is a Hoori in Paradise whose beauty is boasted of by the people of Paradise. Had not Allah, The Exalted, willed that the inhabitants of Paradise will not experience death therein, they would have died of her beauty!" Upon hearing Maalik's statement, ‘Ataa' got depressed. [Haadi Al-Arwaah]

We could not find any statements of scholars that declare this narration as authentic or inauthentic. Assuming that it is authentic, it may be mentioned to encourage people to aspire to the pleasures that Allah has prepared for His believing slaves in Paradise. However, it may not be mentioned as a decisive description of this Hoori except with an authentic hadeeth attributed to the infallible Prophet, sallallaahu ‘alayhi wa sallam.

Allah knows best.