Fasting has always been a recommended act with different levels of emphasis throughout the ages. All the prophets used to stress on the importance of Fasting. Islamic Fasting: In the 2nd year of Hijra in Madina, Fasting was announced as an obligatory duty on Muslims. Prior to the 2nd year of Hijra in Mecca, Muslims used to know about the Fasting and its importance but it was not announced to be Wajib there.
Shaykh Kumail Rajani