Ruling on making up missed days of Ramadan while fasting voluntarily

Question:
The first message in this episode is one that reached the program from the State of Qatar, sent by one of our sisters there. She says: I am a sister to you in Allah, residing in the State of Qatar, and I have several questions. Her first question is: Shaykh Salih, she says, I have days from months of Ramadan that I do not know the number of. I am currently fasting on Mondays and Thursdays, or on Thursdays whenever the opportunity arises. Is that correct, or do I also have to pay an expiation by feeding poor people? May Allah reward you with good.

Answer:
In the name of Allah, the Most Gracious, the Most Merciful. Praise be to Allah, Lord of the worlds, and may Allah send prayers and blessings upon our Prophet Muhammad and his family and his Companions. To proceed: Fasting in Ramadan, fasting the month of Ramadan, is a pillar of Islam, obligatory upon every Muslim who is accountable and capable of fasting. Allah the Exalted said: And the Prophet (peace and blessings be upon him) said: the Sacred House of Allah So Allah made fasting obligatory upon this Ummah: performing it for the one who is present and healthy, or making it up for the one who was traveling or sick, from other days? As for what the questioner mentioned about having days from Ramadan that she broke, whether she did so intentionally without an excuse, or she was excused by menstruation or post-natal bleeding, or she was traveling, or any of the other legal excuses, the important point is that it is obligatory for her to make up the number of days she broke. If she does not know the number, she should estimate it and do her best to estimate it, and fast the number that she believes is most likely the number she broke. In addition to making up the fasts, she must feed one poor person for each day of the delay, and give out the amount of one and a half kilograms of food for the poor for each day, along with repentance to Allah (Glorified and Exalted is He).
As for voluntary fasting, as she mentioned that she fasts on Mondays and Thursdays, it does not suffice. It does not suffice for the fast of Ramadan. It is necessary to make up the fasts with the intention of making up the Ramadan fasts. And his saying (peace and blessings be upon him) , so voluntary fasting does not suffice for the obligatory fast. Therefore, she must fast the days she broke if she knows their number, or if not, she should estimate them and do her best to estimate them, and whatever number of these days she believes is most likely, she should fast that as a make-up. Yes.