question #2 Sahih al-Bukhari 2014, Book 32, Hadith 1 : How does observing the night of Qadr with sincere faith impact one’s past sins?

The Prophet (ﷺ) said, “Whoever fasted the month of Ramadan out of sincere Faith (i.e. belief) and hoping
for a reward from Allah, then all his past sins will be forgiven, and whoever stood for the prayers in
the night of Qadr out of sincere Faith and hoping for a reward from Allah, then all his previous sins
will be forgiven .”