"…and then follows it with six days in Shawwâl" – Before Making Up Missed Days of Ramadan

Abû Ayyûb al-Ansârî relates that Allah's Messenger (peace be upon him) says: "Whoever fasts the month of Ramadan and then follows it with six days in Shawwâl, it will be as if he had fasted the year through." [Sahîh Muslim (1163)]

A Muslim has days of the previous Ramadan fast to make up. Maybe he had been sick for a few days or maybe he had to travel. A woman almost always has days to make up, since she cannot fast when she is on her monthly period. A Muslims who has days like these to make up, is he allowed to observe voluntary fasts before doing so?
This is a question that scholars have always disagreed about. They have expressed three opinions on this matter:
1. It is forbidden to observe a voluntary fast before making up all the days one has missed in Ramadan. This is the ruling adopted by the Hanbalî school of law.
2. It is disliked to do so, but not prohibited. This is the ruling adopted by the Mâlikî and Shâfi`î schools of law.
3. It is permissible to do so. This is the view of the Hanafî school of law. It is also an alternative opinion expressed by Ahmad Ibn Hanbal that was favored by the Hanbalî jurist Ibn Qudâmah.
What appears to me to be the most correct view is that it is permissible to observe the voluntary fasts that have specific timeframes for their observance before making up the days of Ramadan that one has missed, as long as one has a reasonable belief that he will be able to make up those Ramadan fasts later on. These include the fast of `Arafah, the fast of `Ashûrâ', and fasting six days in Shawwâl. It is best to make up the Ramadan fasts first if possible, but it is not necessary to miss these valuable Sunnah fasts because one has yet had a chance to make up those missed Ramadan fasts.
The matter is a flexible one, and the following evidence supports this flexibility:
1. The basic ruling for making up the missed fasts of Ramadan is that there is no fixed time for it. Allah says: "(Fast) for a certain number of other days." [Sûrah al-Baqarah: 184] This shows that the days for making up the missed Ramadan fasts is not specified. Moreover, this verse does not indicate that voluntary fasts are prohibited until these missed days are made up.
2. All the evidence that encourages voluntary fasting is general and does not come with such a restriction. For example, when the Prophet (peace be upon him) instructed his Companions to observe the fast of `Ashûrâ', he simply did so without qualifying it with any provisions or restrictions.
3. `A'ishah relates: "I used to have days from Ramadan which I never managed to make up before the following Sha`bân due to my being busy with Allah's Messenger (peace be upon him)." [Sahîh al-Bukhârî and Sahîh Muslim]
If we allege that it is absolutely necessary for a Muslim to make up the missed days of Ramadan before offering any voluntary fast, this means that `A'ishah must never have observed a voluntary fast! She never would have been able to fast `Ashûrâ' in the month of Muharram. She would never have been able to fast the day of `Arafah in the month of Dhû al-Hijjah. She would never have observed six days of fasting in the month of Shawwâl. This is because all of these fasts take place before the following month of Sha`bân. It is inconceivable that a Companion of the stature of `A'ishah would neglect all of these fasts.
Answering an Argument Specifically Prohibiting the Six Days of Shawwâl
Some scholars have argued that as evidence that the special blessings mentioned in the hadîth of Abû Ayyûb al-Ansârî for fasting six days in Shawwâl can only be realized by someone who has completed all of the Ramadan fasts. They point out that the hadîth states: "Whoever fasts the month of Ramadan and then follows it with six days in Shawwâl, it will be as if he had fasted the year through."
They argue that a person who still has days to make up from Ramadan has not truly fasted "the month or Ramadan".
There are three ways to answer this argument:
1. It can be said of whoever fasts most of the month that he has "fasted the month". The proof for this is that `A'ishah said: "The Prophet (peace be upon him) never used to fast more than he did in the month of Sha`bân. He used to fast all of Sha`bân." [Sahîh al-Bukharî and Sahîh Muslim]
We know that the Prophet (peace be upon him) did not fast every single day of Sha`bân, because the narration in Sahîh Muslim reads: "… He used to fast all of Sha`bân, all of Sha`bân except for a little."
We also have where `A'ishah said: "…so much so that he would observe i`tikâf in the first ten days of Sha`bân" She said this in spite of the fact that the Prophet (peace be upon him) definitely did not observe i`tikâf on the first of those ten days, since that is the day of `Id al-Fitr.
The same can be said for the hadîth wherein `A'ishah said: "He used to fast the ten days of Dhû al-Hijjâh" in spite of the fact that the Prophet (peace be upon him) definitely did not fast on the tenth of those ten days, since that day is `Id al-Adhâ.
This manner of speaking is common in Arabic. It is common usage to refer to the majority of something as "all of it". Ofr this reason, we have two general axioms in Islamic Law:

* Most of something can have the same legal status as all of it.
* Most of something can stand for all of it.

The Hanbalî jurist al-Bahûtî asserts: "Most of something is handled in the same manner as all of it in the majority of Islamic legal rulings."
2. A person who has fasted Ramadan and fully intends to make up whatever days he has justifiably missed, he has the same reward as the person who fasted the whole month without missing any days. Therefore, excluding him from the generality of the statement "Whoever fasts the month of Ramadan" is unjustifiable.
3. If we are to insist that it is absolutely necessary for a Muslim to make up the missed days of Ramadan before observing the six days in Shawwâl, this will force many Muslims to lose out on this important voluntary fast and its immense benefits. This is especially the case for women who have to miss a considerable number of days in Ramadan – six, seven, or even more – on account of menstruation. We must keep in mind that the same woman will be unable to fast in the month of Shawwâl for six or seven days for the same reason. We must also consider that she will not be able to fast the day of `Id and might have to travel or engage in other activities that are customary in the days following `Id. How will she be able to make up all the missed days of Ramadan and still observe an additional six days in Shawwâl? It will be very difficult for her to do so.
Therefore, we say to this woman: Make up the missed days of Ramadan first if it is easy for you to do so. However, if that is something difficult for you, then you should rather observe the six days of Shawwâl first and make up the missed days of Ramadan later on. This conforms with the flexibility and ease that is part of Islamic Law, especially with respect to voluntary worship.
And Allah knows best.