Ruling on fasting seven consecutive days voluntarily

It is permissible
for a person to fast voluntarily for seven days or ten days one after
another, because of the hadeeth of ‘Aa’ishah (may Allah be pleased with
her) who said: The Messenger of Allah (blessings and peace of Allah be
upon him) used to fast until we would say, he will never stop fasting, and
he used not to fast until we would say, he will never fast. I never saw
the Messenger of Allah (blessings and peace of Allah be upon him) fast any
entire month except Ramadan, and I never saw him fast more than he did in
Sha‘baan.

Narrated by
al-Bukhaari (1833) and Muslim (1956). 

According to a report
narrated by Abu Dawood (2313), from Umm Salamah, from the Prophet (blessings
and peace of Allah be upon him): He never fasted a complete month in the
year except Sha‘baan, and he would join Ramadan to it.

Classed as saheeh by
Shaykh al-Albaani in Saheeh Abi Dawood. 

It was also narrated
from her that Hamzah ibn ‘Amr al-Aslami asked the Messenger of Allah
(blessings and peace of Allah be upon him): O Messenger of Allah, I am a man
who fasts several days in a row; can I fast when travelling? He said: “Fast
if you wish and do not fast if you wish.”

Narrated by Muslim,
1890. 

Based on that, it is
permissible to fast continuously for several days of the month in a row;
that is not included in the fasting that is forbidden, namely fasting all
the time. 

We have previously
discussed the ruling on fasting all the time in the answer to question no.
144592 

Shaykh Ibn Jibreen
(may Allah have mercy on him) was asked: What is the ruling on fasting every
day, one after another, because of special circumstances, based on one
interpretation of the hadeeth which says: The Messenger of Allah (blessings
and peace of Allah be upon him) used to fast until we would say, he will
never stop fasting, and he used not to fast until we would say, he will
never fast? How sound is it to quote this hadeeth as evidence? 

He replied: It is
permissible to fast several days in a row, then to not fast for several days
in a row. The evidence for that is the hadeeth mentioned in the question,
because that is voluntary and is mustahabb.

End quote from
Fataawa Ibn Jibreen 

And Allah knows best.