What is the ruling on one who swore to quit smoking, then returned to it?

If the oath is in the form "By Allah, I will not smoke," then breaking it occurs with the first instance of smoking. If the oath is repeated before it is broken, and it is broken only once, then only one expiation for an oath (kaffarat yamin) is required. However, if both the swearing and the breaking are repeated, then an expiation for an oath is required for each oath that was broken. The expiation for an oath is to feed ten poor persons, or to clothe them, or to free a slave. If one is unable to do so, then fasting for three consecutive days is more prudent.