Reference : Hisn al-Muslim 258

وَقَالَ صلى الله عليه وسلم: أَيَعْجِزُ أَحَدُكُم أَنْ يَكْسِبَ كُلَّ يَوْمٍ أَلْفَ حَسَنَةٍ؟ فَسَأَلَهُ سَائِلٌ مِنْ جُلَسَائِهِ كَيْفَ يَكْسِبُ أَحَدُنَا أَلْفَ حَسَنَةٍ؟ قَالَ: يُسَبِّحُ مِائَةَ تَسْبِيحَةٍ، فَيُكتَبُ لَهُ أَلْفُ حَسَنَةٍ أَوْ يُحَطُّ عَنْهُ أَلْفُ خَطِيئَةٍ.
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Allah's Messenger (ﷺ) said:

"Is anyone of you incapable of earning one thousand Hasanah (rewards) in a day?" 
Someone from his gathering asked, "How can anyone of us earn a thousand Hasanah?" 
He said, "Glorify Allah a hundred times and a thousand Hasanah will be written for you, or a thousand sins will be wiped away."

Reference:
Muslim 4/2073.

Chapter: Excellence of Tasbih, Tahmid, Tahlil, and Takbir