Sunan Ibn Majah 3812
سنن ابن ماجه#3812SahihIt was narrated from Abu Hurairah that :the Messenger of Allah (ﷺ) said: "Whoever says: Subhan Allahi wa bi hamdihi (Glory and praise is to Allah) one hundred times, his sins will be forgiven even if they were like the foam of the sea
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Al-AlbaniSahih
Muhammad Fouad Abd al-BaqiSahih
Shuaib Al ArnautSahih
Zubair Ali ZaiSahih
In-book reference: 33:156