Sayyiduna Abu Hurairah (may Allah be pleased with him) narrates: The Prophet Muhammad (peace and blessings be upon him) was asked: Which deed is the most virtuous? The Prophet (peace and blessings be upon him) said: To have faith in Allah and His Messenger. The questioner asked: Then which one? The Prophet (peace and blessings be upon him) said: Striving in the way of Allah is the hump of deeds (i.e., the best of deeds). The questioner asked: Then which one? The Prophet (peace and blessings be upon him) said: An accepted Hajj.
Hadith Referenceصحیح ابن حبان / كتاب السير / 4598
Hadith Gradingفضيلة الشيخ الإمام محمد ناصر الدين الألبانيحسن صحيح - المصدر نفسه: ق دون قوله: «سنام العمل».فضيلة الشيخ العلّامة شُعيب الأرناؤوطإسناده حسن