Riyad as-Salihin, Book 12, Hadith 1287 (In-Book)

Abu Dharr (May Allah be pleased with him) reported: The Messenger of Allah was asked: "Which deed is the best?" He replied, "Faith in Allah and Jihad (fighting, struggle) in the Cause of Allah."[Al-Bukhari and Muslim].

وعن أبي ذر رضي الله عنه قال‏:‏ قلت يا رسول الله أي العمل أفضل‏؟‏ قال‏:‏ ‏ "‏الإيمان بالله والجهاد في سبيله‏" ‏ ‏(‏‏(‏متفق عليه‏)‏‏)‏

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