Is it permissible to perform voluntary fasting before the fasting for expiation?

Question:
May Allah reward you. This questioner says: Honorable Shaykh, is it permissible to perform voluntary fasting before the fasting for the expiation of an oath, such as fasting on the Day of 'Arafah, the Day of Ashura, and the six days of Shawwal?

Answer:
The fasting that is missed is brought forward. Fasting on the Day of 'Arafah is missed, and fasting on the Day of Ashura is missed, so the one that is missed is brought forward. The expiation for an oath is not missed, so he fasts it if he does not have food, and is not able to feed, or to free a slave, or to clothe ten poor people. In that case, he fasts for three days. However, if a day passes that is missed, and it is one of the days for which it is recommended to fast, such as the Day of 'Arafah, or Thursday, or Monday, or the six days of Shawwal, or the Day of Ashura, then he brings forward the fasting that is missed, whose virtue is lost, before the fasting for expiation; because the expiation is spacious. Yes.