What he told the bedouins who asked whether treatment was allowed
They kept asking whether ordinary things were sinful.
تَدَاوَوْا عِبَادَ اللَّهِ فَإِنَّ اللَّهَ سُبْحَانَهُ لَمْ يَضَعْ دَاءً إِلاَّ وَضَعَ مَعَهُ شِفَاءً
Tadāwaw ʿibāda-Llāh, fa-inna-Llāha subḥānahu lam yaḍaʿ dāʾan illā waḍaʿa maʿahu shifāʾan
“Seek treatment, servants of Allah. Allah has put down no disease without putting down a cure with it.”
The same hadith adds one exception to the cures: old age.
Where this comes from
They came asking whether this or that was a sin. He told them Allah had lifted the difficulty, except from the man who takes something from his brother's honour. Then someone asked whether seeking medical treatment counted as a lack of trust. He answered with an instruction, not a permission.
The full narration
It was narrated that Usamah bin Sharik said:“I saw the Bedouins asking the Prophet (ﷺ): ‘Is there any harm in such and such, is there any harm in such and such?’ He said to them: ‘O slaves of Allah! Allah has only made harm in that which transgresses the honor of one’s brother. That is what is sinful.’ They said: ‘O Messenger of Allah! Is there any sin if we do not seek treatment?’ He said: ‘Seek treatment, O slaves of Allah! For Allah does not create any disease but He also creates with it the cure, except for old age.’ They said: ‘O Messenger of Allah, what is the best thing that a person may be given?’ He said: ‘Good manners.’”
Source
Sunan Ibn Mājah · 3436
- Al-Albani: Sahih
- Muhammad Fouad Abd al-Baqi: Sahih
- Shuaib Al Arnaut: Hasan Sahih
- Zubair Ali Zai: Isnaad Sahih