Prioritizing the fast of a vow over the recommended fast

You also ask and say: It happened that I fell ill and I vowed that if I were healed from it, I would fast fifteen days for Allah the Mighty and Majestic, without specifying a time. I have been healed, praise be to Allah, and I started fasting in the month of Rajab. I fasted five days and got tired, then I fasted five days in Sha'ban and got tired. After Ramadan, I am accustomed to fasting the six days of Shawwal, so I ask: Should I fast the six days of Shawwal first, and then fast the vow, or what?
Answer: You must first complete the remainder of the vow, and then fast the six days of Shawwal if you are able to do so. If you leave them, there is no harm; because fasting the six days of Shawwal is recommended (mustahabb) and not obligatory (wajib). As for fasting for the vow, it is an obligatory (wajib) duty (fard). Therefore, it is obligatory for you to begin with the obligatory (fard) before the voluntary (nafilah). If you intended to fast them consecutively, meaning that you fast the fifteen days in a row, then you must fast them consecutively, and separating them is not sufficient. Rather, you must fast them consecutively, and the previous fasting is void. However, if you did not intend to fast them consecutively, then you are obligated to fast the remainder, which is five days, which you fast, if Allah wills, and the matter is concluded. It is not befitting for you to make vows after this. Vowing is not befitting. The Prophet (peace and blessings be upon him) said: Therefore, it is not befitting to make vows, neither for the sick nor for the non-sick. But whenever a person vows obedience to Allah, it becomes obligatory for him to fulfill it, such as fasting and prayer; due to the saying of the Prophet (peace and blessings be upon him): narrated by al-Bukhari in the Sahih.
So when a person vows to fast a specific number of days, or to pray two rak'ahs, or to give charity with a certain amount of money, he is bound to fulfill what he vowed of acts of obedience; because Allah praised the believers and said, the Exalted: [Al-Insan:7] And because the Messenger (peace and blessings be upon him) commanded the fulfillment of vows: But he has no right to vow, and it is not befitting for him to vow; due to the aforementioned hadith, his saying (peace and blessings be upon him): Vowing is not a cause for healing, nor a cause for obtaining the desired need, so there is no need for vowing. But it is something that a person imposes on himself, and it extracts from the miser. Then after this, he regrets and strains himself afterwards, and he wishes he had not vowed. So the Shari'ah, by the praise of Allah, came with what is more comfortable for people and more beneficial for people, which is the prohibition of vowing. Yes.
The presenter: May Allah reward you.