Riyad as-Salihin, Book 9, Hadith 1176 (In-Book)

Jabir (May Allah be pleased with him) reported: The Messenger of Allah was asked: "Which Salat is the best?" He replied, " The best Salat is that in which Qiyam (the duration of standing) is longer."[Muslim].

وعن جابر رضي الله عنه قال‏:‏ سئل رسول الله صلى الله عليه وسلم ‏:‏ أي الصلاة أفضل‏؟‏ قال‏:‏ ‏ "‏طول القنوت‏" ‏ ‏(‏‏(‏رواه مسلم‏)‏‏)‏‏.‏

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