I used to smoke and I swore by Allah to quit, but I returned to it after a year. Then I regretted it and swore again, fasted for three days, and fed the students of one of the schools.

The questioner : He says, “O honorable Shaykh, I used to smoke and I swore by Allah to quit, but I returned to it after a year. Then I regretted it and swore again, fasted for three days, and fed the students of one of the remote schools. Then I returned to it after more than a year, regretted it, and quit. I fasted and fed people. Is there a great sin on me for this behavior?”

The Shaykh : It is obligatory for one who swears not to commit a sin to stand firm on his oath and not to disobey Allah (Mighty and Majestic). If he returns to the sin despite his oath not to commit it, he must pay the expiation for an oath, which is: freeing a slave, or feeding ten poor people, or clothing them.
Fasting does not suffice as the expiation for an oath except for one who is unable to do these three things: freeing a slave, feeding, and clothing. As for one who is able, even if he fasts for three months, it does not suffice for him.
I advise this brother to be strong in his resolve, firm, and not to sit with the people of the sin from which he repented, but rather to stay away from them until that [resolve] becomes settled in his heart.