Is expiation (kaffarah) obligatory for one who swore by Allah not to return to a sin, and then returned to it?

This person is obligated to repent to Allah with a repentance that includes abandoning the sin, resolving not to return to it, and regretting having committed it. He must also offer an expiation for breaking his oath (kaffarat yameen), which is feeding ten needy persons, or clothing them, or freeing a slave. If he is unable to do so, then he must fast for three consecutive days, as Allah Almighty says: "Allah will not impose blame upon you for what is unintentional in your oaths, but He will impose blame upon you for what you intended of oaths. So its expiation is the feeding of ten needy people from the average of that which you feed your [own] families or clothing them or the freeing of a slave. But whoever cannot find [or afford it] - then a fast of three days. That is the expiation for oaths when you have sworn. And guard your oaths. Thus does Allah make clear to you His verses that you may be grateful." (Al-Ma'idah: 89).