حَدَّثَنِي عَنْ مَالِكٍ، عَنْ زَيْدِ بْنِ أَسْلَمَ، عَنْ عَطَاءِ بْنِ يَسَارٍ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ ‏"‏ إِذَا مَرِضَ الْعَبْدُ بَعَثَ اللَّهُ تَعَالَى إِلَيْهِ مَلَكَيْنِ فَقَالَ انْظُرَا مَاذَا يَقُولُ لِعُوَّادِهِ ‏.‏ فَإِنْ هُوَ - إِذَا جَاءُوهُ - حَمِدَ اللَّهَ وَأَثْنَى عَلَيْهِ رَفَعَا ذَلِكَ إِلَى اللَّهِ عَزَّ وَجَلَّ - وَهُوَ أَعْلَمُ - فَيَقُولُ لِعَبْدِي عَلَىَّ إِنْ تَوَفَّيْتُهُ أَنْ أُدْخِلَهُ الْجَنَّةَ وَإِنْ أَنَا شَفَيْتُهُ أَنْ أُبْدِلَ لَهُ لَحْمًا خَيْرًا مِنْ لَحْمِهِ وَدَمًا خَيْرًا مِنْ دَمِهِ وَأَنْ أُكَفِّرَ عَنْهُ سَيِّئَاتِهِ ‏"‏ ‏.‏

Yahya related to me from Malik from Zayd ibn Aslam from Ata ibnYasar that the Messenger of Allah, may Allah bless him and grant himpeace, said, "When the slave is ill, Allah ta'ala sends two angels tohim." He said, "They look at what he says to his visitors. If hepraises Allah and lauds Him, when they come to him, they take that upto Allah, the Mighty, the Majestic, and He knows best, and He says,'If I make my slave die, I will make him enter the Garden. If I healhim, I will replace his flesh with better flesh and his blood withbetter blood and I will efface his evil actions.'" Translation Not Available

Book reference: Muwatta Imam Malik Book 50 Hadith 1718
Web reference: Muwatta Imam Malik Book 50 Hadith 5