Sahih Bukhari Volume 004, Book 056, Hadith Number 665.
Hadith Section/Book: Sahih Bukhari Sahih Bukhari Book 56. Virtues and Merits of the Prophets (PBUH) and his Companions
Narated By Ibn Umar : Allah's Apostle said, "Your period (i.e. the Muslims' period) in comparison to the periods of the previous nations, is like the period between the 'Asr prayer and sunset. And your example in comparison to the Jews and the Christians is like the example of a person who employed some laborers and asked them, 'Who will work for me till midday for one Qirat each?' The Jews worked for half a day for one Qirat each. The person asked, 'Who will do the work for me from midday to the time of the 'Asr (prayer) for one Qirat each?' The Christians worked from midday till the 'Asr prayer for one Qirat. Then the person asked, 'Who will do the work for me from the 'Asr till sunset for two Qirats each?' " The Prophet added, "It is you (i.e. Muslims) who are doing the work from the Asr till sunset, so you will have a double reward. The Jews and the Christians got angry and said, 'We have done more work but got less wages.' Allah said, 'Have I been unjust to you as regards your rights?' They said, 'No.' So Allah said, 'Then it is My Blessing which I bestow on whomever I like."