Sahih Bukhari Volume 006, Book 061, Hadith Number 539.
Narrated By Ibn 'Umar : The Prophet said, "Your life in comparison to the lifetime of the past nations is like the period between the time of 'Asr prayer and sunset. Your example and the example of the Jews and Christians is that of person who employed laborers and said to them, "Who will work for me till the middle of the day for one Qirat (a special weight)?' The Jews did. He then said, "Who will work for me from the middle of the day till the 'Asr prayer for one Qirat each?" The Christians worked accordingly. Then you (Muslims) are working from the bar prayer till the Maghrib prayer for two Qirats each. They (the Jews and the Christians) said, 'We did more labor but took less wages.' He (Allah) said, 'Have I wronged you in your rights?' They replied, 'No.' Then He said, 'This is My Blessing which I give to whom I wish."