كتاب الذكر والدعاء والتوبة والاستغفار
48
The Book Pertaining to the Remembrance of Allah, Supplication, Repentance and Seeking Forgiveness
(10)
Chapter: The Virtue Of Tahlil (Saying La Ilaha Ill-Allah), Tasbih (Saying Subhan Allah) And (Du'a) Supplication
(10)
باب فَضْلِ التَّهْلِيلِ وَالتَّسْبِيحِ وَالدُّعَاءِ
Sahih Muslim 2698

Mus'ab b. Sa'd reported that his father told him that he had been in the company of Allah's Messenger (ﷺ) that he said:

Is one amongst you powerless to get one thousand virtues every day. Amongst those who had been sitting there, one asked: How one amongst us can get one thousand virtues every day? He said: Recite:" Hallowed be Allah" one hundred times for (by reciting them) one thousand virtues are recorded (to your credit) and one tbousand vices are blotted out.
حَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ، حَدَّثَنَا مَرْوَانُ، وَعَلِيُّ بْنُ مُسْهِرٍ، عَنْ مُوسَى الْجُهَنِيِّ، ح وَحَدَّثَنَا مُحَمَّدُ بْنُ عَبْدِ اللَّهِ بْنِ نُمَيْرٍ، - وَاللَّفْظُ لَهُ - حَدَّثَنَا أَبِي، حَدَّثَنَا مُوسَى الْجُهَنِيُّ، عَنْ مُصْعَبِ بْنِ سَعْدٍ، حَدَّثَنِي أَبِي قَالَ، كُنَّا عِنْدَ رَسُولِ اللَّهِ صلى الله عليه وسلم فَقَالَ ‏"‏ أَيَعْجِزُ أَحَدُكُمْ أَنْ يَكْسِبَ كُلَّ يَوْمٍ أَلْفَ حَسَنَةٍ ‏"‏ ‏.‏ فَسَأَلَهُ سَائِلٌ مِنْ جُلَسَائِهِ كَيْفَ يَكْسِبُ أَحَدُنَا أَلْفَ حَسَنَةٍ قَالَ ‏"‏ يُسَبِّحُ مِائَةَ تَسْبِيحَةٍ فَيُكْتَبُ لَهُ أَلْفُ حَسَنَةٍ أَوْ يُحَطُّ عَنْهُ أَلْفُ خَطِيئَةٍ ‏"‏ ‏.‏
Reference : Sahih Muslim 2698
In-book reference : Book 48, Hadith 47
USC-MSA web (English) reference : Book 35, Hadith 6517
  (deprecated numbering scheme)