ENOfficial
Isma'il ibn Qays said, "I came to Khabbab when he had been cauterised seven times. He said, 'If it had not been that the Messenger of Allah, may Allah bless him and grant him peace, had forbidden us to pray for death, I would have done so.'"
Source: sunnah.com
Other translations
Arabic
حَدَّثَنَا مُسَدَّدٌ، قَالَ: حَدَّثَنَا يَحْيَى، عَنْ إِسْمَاعِيلَ قَالَ: حَدَّثَنِي قَيْسٌ قَالَ: أَتَيْتُ خَبَّابًا، وَقَدِ اكْتَوَى سَبْعًا، وَقَالَ: لَوْلاَ أَنَّ رَسُولَ اللهِ صلى الله عليه وسلم نَهَانَا أَنْ نَدْعُوَ بِالْمَوْتِ لَدَعَوْتُ بِهِ.
sunnah.com