Abu Huraira reported that God's Messenger said to Bilal at the dawn prayer, “Tell me, Bilal, of the action you have done since becoming a Muslim which is most calculated to cause hope in you, for I heard the sound of your sandals in front of me in paradise.” He replied, “I have done no action more calculated, in my opinion to cause hope than that I have never performed ablution at any hour of the night or day without immediately praying what was ordained for me to pray.” (Bukhari and Muslim.)
Hadith Referenceمشكوة المصابيح / كتاب الصلاة / 1322
Hadith Gradingالألبانی:مُتَّفَقٌ عَلَيْهِ | زبیر علی زئی:متفق عليه
Hadith Takhrij´تحقيق و تخريج: محدث العصر حافظ زبير على زئي رحمه الله` «متفق عليه، رواه البخاري (1149) و مسلم (2458/108)»