Narrated Abu Hurairah رضي الله عنه : Allâh’s Messenger صلى الله عليه وسلم said, “If anyone of you improves (follow strictly) his Islâmic religion, then his good deeds will be rewarded ten times to seven hundred times for each good deed and a bad deed will be recorded as it is.
(Sahīh Al-Bukhârī, Vol. 1,
Hadīth No. 40B)
Translated by Dr. Muhammad Taqî –ud-Dî n Al-Hilâlī & Dr. Muhammad Muhsin Khân , p. 268 (under footnote), The Noble Qur’ân