The Book Pertaining to the Remembrance of Allah, Supplication, Repentance and Seeking Forgiveness
Ṣaḥīḥ Muslim 6852
يُسَبِّحُ مِائَةَ تَسْبِيحَةٍ فَيُكْتَبُ لَهُ أَلْفُ حَسَنَةٍ أَوْ يُحَطُّ عَنْهُ أَلْفُ خَطِيئَةٍ
yusabbiḥu māʾaha tasbīḥatin fayuktabu lah alfu ḥasanatin aw yuḥaṭṭu ʿanhu alfu khaṭīʾatin
Transliteration generated from the Arabic vowel marks
The full narration
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
Source
Ṣaḥīḥ Muslim · 6852