Warning that opening the door of precaution in religion is opening a major door to adding to the religion.

The Shaykh : Opening the door of precaution in religion is opening a major door to adding to the religion, and in reality, there are many examples of this regarding certain jurisprudential rulings.
Perhaps those present know that some schools of jurisprudence obligate one who prays on Friday to pray the midday prayer after finishing it. Some schools obligate this, but other schools do not obligate it for the reason the first school gives, which is that the prayer was not valid, so this one is prayed. However, this other school says: there are conditions regarding which there is disagreement; if they are met, the Friday prayer is valid, and if they are not met, the prayer is not valid. So, as a precaution, it is good to pray the midday prayer after Friday.
This precaution leads its proponent to contradict what is known from the religion by necessity, namely that Allah (Mighty and Majestic) only made obligatory five prayers in every day and night, and to contradict another text, which is His saying (peace and blessings be upon him): . We know that what is obligatory on Friday is the Friday prayer. If the Friday prayer is not valid like the midday prayer, then praying twice, once with the intention of Friday and once with the intention of midday, contradicts this hadith and that which is known from the religion by necessity. The hadith says: . So, in the same time slot, the time of midday, he prayed two prayers: the Friday prayer and then the midday prayer. Therefore, it is not permissible for a person to precede the ruling specified in the Shari'ah in the name of precaution or in the name of what the common people say: "adding to good is good." There is no good after what Allah (Mighty and Majestic) legislated through the tongue of His Prophet (peace and blessings be upon him) of good.
In summary: this hadith, in the context where the Muslim is prohibited from preceding Ramadan by fasting one or two days, clarifies that there is no objection to fasting what was his custom before Ramadan. If it is his custom to fast, for example, three days of every month, and Ramadan comes, he may fast these three days. He may fast two days, he may fast one day, as long as he did not intend to fast specifically for Ramadan. Because Ramadan has a limited number of days, he fasted only to carry out that prescribed custom he was accustomed to.
Thus, this hadith, whose authenticity is agreed upon by scholars, directly covers the disagreement among scholars regarding fasting the day of doubt. Some of them say it is legislated, also as a precaution, and some say: fasting it is not legislated. The aforementioned hadith is evidence and support for the position that says fasting the day of doubt is not legislated. This is because it will come in the authentic hadiths that Ramadan is established by sighting the moon. If there is no sighting, then completing the month, i.e., the month of Sha'ban, is thirty days. So why would a person fast the day of doubt?