Sayyiduna Abu Hurairah (may Allah be pleased with him) narrates: The Prophet (peace and blessings be upon him) asked Sayyiduna Bilal (may Allah be pleased with him) at the time of the Fajr prayer: O Bilal, tell me about the deed you have done after embracing Islam for which you have the greatest hope (of reward), because I heard the sound of your footsteps ahead of me in Paradise last night. Sayyiduna Bilal (may Allah be pleased with him) replied: I have not done any deed for which I have greater hope, except that whenever I perform ablution, I do so thoroughly, whether it is any part of the night or day, and then after that, as much as is destined for me, I offer voluntary prayers. The narrator named Abu Usamah, confirming this narration, said: Yes.
Hadith Referenceصحیح ابن حبان / كتاب إخباره ﷺ عن مناقب الصحابة رجالهم ونسائهم بذكر أسمائهم رضوان الله عليهم أجمعين / 7085
Hadith Gradingفضيلة الشيخ الإمام محمد ناصر الدين الألبانيصحيح - «الإرواء» (2/ 221): ق.فضيلة الشيخ العلّامة شُعيب الأرناؤوطإسناده صحيح على شرط الشيخين