Ibn Rajab rahimahullah said, getting closer to Allah Ta'ala by leaving the case that was originally changed was not perfect until someone left an illegal act. Whoever does what is unlawful is accompanied by drawing closer to Allah by leaving the changed, so this is the same as someone leaving the obligatory and then turning to work on the sunnah. Even though the fasting of the person who is committing is still considered legitimate and is not ordered to mengqadha 'fast in the opinion of jumhur (the majority of scholars). The reason is because the practice is nullified if someone commits an act that is prohibited due to special reasons (such as eating, drinking and drinking) and is not null and void if he does a prohibited act which is not due to a specific reason. This is the opinion of the majority of scholars.
Ibn Hajar rahimahullah said, "Avoiding various things that can cancel fasting, the law is obligatory. Whereas staying away from things other than those classified as immoral includes perfecting fasting. "
Mulla ‘Ali Al Qori rahimahullah said," When fasting is so hard it is forbidden to engage in mockery. The person who fasts but commits immorality is the same as the person who is hajj then pretends, namely the principal reward is not nullified, only the perfection of the reward that he does not obtain. A person who fasts but has a mockery will get the reward of fasting as well as sin because of the immorality he committed. "
