رِيَاضُ الصَّالِحِينَ
Riyad as-Salihin 1655
The Book of the Prohibited actions
Prohibition of putting oneself to Undue Hardship
وَعَنِ ابْنِ عُمَرَ رَضِيَ اللَّهُ عَنْهُمَا قَالَ : نهينا عَنْ التكلف . ((رَوَاهُ الْبُخَارِيّ)).
'Umar (May Allah be pleased with him) said: We have been forbidden to go into excess. [Al-Bukhari].
Riyad as-Salihin, 1655