ما هي الكفارة الواجبة على من حلف على المصحف بترك معصية ثم عاد إليها؟

It is obligatory to perform sincere repentance from the sin, to resolve to abandon it, and to feel remorse for what has passed, along with the obligation of an expiation for breaking an oath (kaffarat yamin). If you are unable to provide the expiation, then fast for three days, as Allah the 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 poor people from the average of that which you feed your [own] families or clothing them or freeing a slave. But whoever finds not [the means to do so] – 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).