It is narrated from Sayyiduna Abu Musa (may Allah be pleased with him) that the Prophet (peace and blessings be upon him) said: "When the people of the Fire are gathered in Hell, and with them are those of the people of the Qiblah (the Muslims) whom Allah wills, the disbelievers will say (to the Muslims): 'What has your accepting Islam availed you, when you too are now with us in Hell!' They will reply: 'We had some sins, and we were seized for them.' Allah Almighty will hear this conversation of theirs, so He will command that the people of the Qiblah who are in Hell be taken out. Seeing this, the disbelievers will say: 'Would that we too had been Muslims, so that we too would have been taken out (of Hell) in the same way,'" and the Messenger of Allah (peace and blessings be upon him) recited this verse: "Alif Lam Ra. These are the verses of the Book and a clear Qur'an. Perhaps those who disbelieve will wish that they had been Muslims." [Surah al-Hijr: 1 - 2] Here he (peace and blessings be upon him) recited the word "rubbama" with a shaddah (doubling) on the letter ba. This hadith has an authentic (sahih) chain of narration, but the two Shaykhs (Bukhari and Muslim) did not record it.