كتاب القدر
46  
The Book of Destiny
(1)
Chapter: How The Human Being Is Created, In His Mother's Womb, And His Provision, Lifespan And Deeds Are Written Down, And His Misery and Happiness
(1)
بَاب كَيْفِيَّةِ خَلْقِ الْآدَمِيِّ فِي بَطْنِ أُمِّهِ وَكِتَابَةِ رِزْقِهِ وَأَجَلِهِ وَعَمَلِهِ وَشَقَاوَتِهِ وَسَعَادَتِهِ
Sahih Muslim 2648 a

Jabir reported that Suriqa b. Malik b. Ju'shuin came and said:

Allah's Messenger, explain our religion to us (in a way) as if we have been created just now. Whosoever deeds we do today, is it because of the fact that-the pens have dried (after recording them) and the destitiles have began to operate or these have effects in future? Thereupon he said: The pens have dried tmd destinies have begun to operate. (Suraqa b. Malik) said: If it Is so, then what is the use of doing good deeds? Zuhair said: Then Abu Zubair said something but I could not understand that and I said. What did he say? Thereupon he said: Act, for everyone is facilitated what he intends to do.
حَدَّثَنَا أَحْمَدُ بْنُ يُونُسَ، حَدَّثَنَا زُهَيْرٌ، حَدَّثَنَا أَبُو الزُّبَيْرِ، ح وَحَدَّثَنَا يَحْيَى بْنُ يَحْيَى، أَخْبَرَنَا أَبُو خَيْثَمَةَ، عَنْ أَبِي الزُّبَيْرِ، عَنْ جَابِرٍ، قَالَ جَاءَ سُرَاقَةُ بْنُ مَالِكِ بْنِ جُعْشُمٍ قَالَ يَا رَسُولَ اللَّهِ بَيِّنْ لَنَا دِينَنَا كَأَنَّا خُلِقْنَا الآنَ فِيمَا الْعَمَلُ الْيَوْمَ أَفِيمَا جَفَّتْ بِهِ الأَقْلاَمُ وَجَرَتْ بِهِ الْمَقَادِيرُ أَمْ فِيمَا نَسْتَقْبِلُ قَالَ ‏"‏ لاَ ‏.‏ بَلْ فِيمَا جَفَّتْ بِهِ الأَقْلاَمُ وَجَرَتْ بِهِ الْمَقَادِيرُ ‏"‏ ‏.‏ قَالَ فَفِيمَ الْعَمَلُ قَالَ زُهَيْرٌ ثُمَّ تَكَلَّمَ أَبُو الزُّبَيْرِ بِشَىْءٍ لَمْ أَفْهَمْهُ فَسَأَلْتُ مَا قَالَ فَقَالَ ‏"‏ اعْمَلُوا فَكُلٌّ مُيَسَّرٌ ‏"‏ ‏.‏
Reference : Sahih Muslim 2648a
In-book reference : Book 46, Hadith 13
USC-MSA web (English) reference : Book 33, Hadith 6402
  (deprecated numbering scheme)