Abdullah ibn Mas’ud reported: I entered upon the Messenger of Allah, peace and blessings be upon him, while he was suffering from fever. I said, “O Messenger of Allah, you are suffering from a strong fever.” The Prophet said, “Yes. I suffer from fever as much as two men among you.” I said, “Is that because you will have a double reward?” The Prophet said, “Yes it is so. There is no Muslim who is afflicted with pain as much as the prick of a thorn or more except that Allah will expiate his sins just as leaves fall from a tree.”

Source: Sahih Bukhari 5324, Sahih Muslim 2571

Grade: Muttafaqun Alayhi (authenticity agreed upon) according to Al-Bukhari and Muslim

عَنْ عَبْدِ اللَّهِ قَالَ دَخَلْتُ عَلَى رَسُولِ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ وَهُوَ يُوعَكُ فَقُلْتُ يَا رَسُولَ اللَّهِ إِنَّكَ لَتُوعَكُ وَعْكًا شَدِيدًا قَالَ أَجَلْ إِنِّي أُوعَكُ كَمَا يُوعَكُ رَجُلَانِ مِنْكُمْ قُلْتُ ذَلِكَ أَنَّ لَكَ أَجْرَيْنِ قَالَ أَجَلْ ذَلِكَ كَذَلِكَ مَا مِنْ مُسْلِمٍ يُصِيبُهُ أَذًى شَوْكَةٌ فَمَا فَوْقَهَا إِلَّا كَفَّرَ اللَّهُ بِهَا سَيِّئَاتِهِ كَمَا تَحُطُّ الشَّجَرَةُ وَرَقَهَا

5324 صحيح البخاري كتاب الأشربة باب أشد الناس بلاء الأنبياء ثم الأمثل فالأمثل

2571 صحيح مسلم كتاب البر والصلة والآداب باب ثواب المؤمن فيما يصيبه من مرض أو حزن أو نحو ذلك حتى الشوكة يشاكها