Explanation of the hadith of Abu Hurayrah: “Do not anticipate Ramadan by fasting one day or two days”

The Shaykh : He said (may Allah have mercy on him): The Book of Fasting:
From Abu Hurayrah (may Allah be pleased with him), who said: The Messenger of Allah (peace and blessings be upon him) said: It is agreed upon by al-Bukhari and Muslim.
In this hadith, there is an explicit prohibition against anticipating Ramadan by fasting one day or more than one day. This falls under the category of preserving the prescribed amount for fasting, which is the month of Ramadan. Therefore, it is not permissible for a Muslim to add to Ramadan, whether by anticipating it or delaying it, by one day or two days. In reality, although this hadith specifically addresses the prohibition of anticipating Ramadan and connecting days of Sha'ban to the month of Ramadan, it contains a strong hint that it is not permissible to add to an obligatory act of worship. This is an explicit ruling prohibiting a man from anticipating Ramadan by fasting one day or two days. Included in this, without a doubt, is fasting the Day of Doubt, as will be mentioned in the following hadith. This prohibition against anticipating Ramadan by fasting one day or two days affirms the obligation to preserve the worship as it was legislated, without addition or reduction. What Allah (Mighty and Majestic) has made obligatory upon His believing servants is only the fasting of the month of Ramadan, which may be thirty days at times and twenty-nine days at other times. Therefore, it is not permissible to anticipate it by fasting one day or two days for fear that Ramadan will become more than thirty days with the passage of time and the lapse of the era of Muslims with knowledge of the Book and the Sunnah.
So I say: At the time when this hadith explicitly prohibits anticipating Ramadan by fasting one day or two days, likewise, no act of worship should be anticipated, just as it is not permissible to connect it with other acts of worship and obedience that are not part of it. There must be a separation that ensures the independence of this obligatory fast, which is the fasting of Ramadan. There must be a separation by breaking the fast before it and after it, so that it is established that this obligation is only the obligation of Ramadan; nothing anticipates it, and nothing is connected to it.