Fasting
Surah 2 (Al-Baqarah/The Cow): 185
Ramadhan is the month during which the Qur´an was revealed. It is (not only) the guidance for mankind, (but is also) the self-evident proof of (the truth of) that guidance, and (it is) the criterion (of the right and the wrong conduct).
Whoever among you lives to see that month, must observe fasts (during that month).
Whoever among you is sick or on a journey, (must fast) the same number of other days. Allah wants to make matters easy for you; He does not want to impose hardships on you.
So complete the period (of fasting). Glorify Allah (and thank Him) for the guidance He has granted.
Perhaps, you would be grateful!
The obligation to fast and to abstain from sex, from dawn to dusk, during the lunar month of Ramadan is contained in {2.183-187}. ‘As it was prescribed for those before you’, {2.183}, probably relates to the two Jewish fast days of Yom Kippur/the Day of Atonement and Tisha B’Av (during which past catastrophes that have befallen the Jewish people are commemorated). The requirement to fast is not explicit in the Torah, but, in relation to Yom Kippur, Leviticus 23.26-32 † requires mortification of the flesh, making offerings to God and the abstention form work ‘from evening to evening’. In practice Judaism interprets this as a requirement to abstain from consumption of food or drink and certain other activities including sexual relations.