Sahih Bukhari Volume 9, Book 93, Hadith Number 587.

Narrated By Abu Huraira : Allah’s Apostle said, “We (Muslims) are the last (to come) but will be the foremost on the Day of Resurrection.” The narrators of this Hadith said: Allah said (to man), ‘Spend (in charity), for then I will compensate you (generously).'”