THE FIQH DEPARTMENT

In the Name of Allah, The Most Beneficent, The Most Merciful.
Although every Fiqh opinion is based on evidence, often times, the scholars differ in their views. This room for differences is a mercy from Allah, and as long as there is evidence to support an opinion, then we must respect scholars' views, even if we may not always agree.
The Prophet (SAW) said:
"Whoever performs Ijtihad and errs will receive one reward. Whoever performs Ijtihad and arrives at the correct answer gets double the reward"
(Bukhari) 
She Fasted During Her Days of Menstration PDF Print E-mail
Fiqh: Islamic Jurisprudence - Ramadan
Written by Muhammad bin Saalih al-`Uthaymeen   

Question:

A young girl had her menstrual period and she was fasting during the days of menstruation due to ignorance; what in incumbent upon her?

Answer:


She must make up for the days which she fasted while she was menstruating, because fasting on the days of menstruation is not accepted, and it is invalid, even if she was ignorant, and there is no limit to the time for making up missed fasts.

And there is another question opposite to this one: A women whose period came to her when she was young and she was embarrassed to tell her family, so she was not fasting. It is incumbent upon this young girl to make up for the month which she did not fast, because when a girl begins to menstruate, she becomes legally responsible, since menstruation is one of the signs of reaching maturity. 

Shaykh Muhammad bin Saalih al-`Uthaymeen

Islamic Verdicts on The Pillars of Islaam, vol.2, page 630