8a] For whom is fasting Ramadaan obligatory?

8a]
As Ibn 'Abbaas (may Allaah be pleased with him) interpreted it, it
refers to the old man and old woman who are not able to fast, so they
should feed one poor person for each day.
The fourth condition:
He should be settled (not travelling). If he is travelling then it is
not obligatory for him to fast, because Allaah says (interpretation of
the meaning):
"and whoever is ill or on ajourney, the same number[of days which one
did not observe Sawm (fasts) must be made up] from other days"
[al-Baqarah 2:185]
The scholars are agreed that it is permissible for a traveller not to fast.
It is better for the traveller to do that which is easier. If fasting
is likelyto be harmful then it becomes haraam to fast, because Allaah
says (interpretation of the meaning):
"And do not kill yourselves (nor kill one another). Surely, Allaah is
Most Merciful to you"
[al-Nisa' 4:29]
This indicates that whatever is harmful to a person is forbidden to
him. See also question no. 20165 .
If you ask, what is the degree of harm which makes fasting haraam?
The answer is:
Harm may be physical, or someone advises him thatfasting may harm him.
With regard to physical harm, that means that thesick person feels
that fasting is harming him and causing him pain, andwill delay his
recovery and so on.
With regard to being advised, this means that aknowledgeable and
trustworthy doctor tells him that it will harm him.
The fifth condition:
There should be no impediments. This appliesspecifically to women.
Women who are menstruating or bleeding following childbirth should not
fast, because the Prophet (peace and blessings of Allaah be upon him)
said: "Is it not the case that when she gets her period, she does not
pray or fast?"
So she should not fast andher fast is not valid in this case,
according to scholarly consensus. And she has to make up the days
missed, also according to scholarly consensus.
Al-Sharh al-Mumti', 6/330.
And Allaah knows best.