The Ruling on Voluntary Fasting Before Making Up Ramadan

Question : Voluntary fasting before making up Ramadan

Answer : There is no doubt that this is contrary to what is preferred. Because reason dictates that the obligatory should come before the voluntary, because the obligatory occupies the conscience, while the voluntary does not. It is agreed upon that it is preferable to begin with making up the missed days before doing voluntary acts. However, if one performs voluntary fasting before making up the missed days, is that valid or not? Some scholars hold that it is not valid. Because...
It is narrated from Abu Bakr (may Allah be pleased with him) that Allah .
And because the permissibility of delaying the making up of missed days is for the sake of leniency toward the one obligated, and it is not wise to be lenient with him regarding the obligatory and then allow him to do voluntary acts. Therefore, it is not valid to perform voluntary fasting until he has made up Ramadan.
A discussion regarding voluntary acts other than the six days of Shawwal. This is the point of disagreement. Those who say it is permissible say so because this obligatory duty is spacious. Until when?
Until there remains in Sha'ban an amount equal to what he owes. And if the obligatory duty is spacious, then voluntary acts before it are valid, like prayer in its time. The obligatory prayer has a spacious time, and if one does voluntary prayer before praying the obligatory, it is valid. And on this basis, they say that voluntary fasting before making up the missed days is permissible because it is a spacious obligatory duty. Yes, if it were restricted, we would say only the obligatory is valid. But if it is spacious, the matter is broad. However, the most cautious view is that it is not permissible to do voluntary acts until he has made up what he owes.