The fast has three fards:

1. Niyya (to intend);
2. To know the earliest time of the niyya, as well as its latest time;
3. To fend off the things that will break the fast starting from dawn (fajr sâdiq) up to sunset, [that is, within the shar’î daytime].

Hadrat Imâm-i Rabbânî says in the 87th letter of the second volume of his Maktûbât:

In other words, each Muslim’s first duty is to obey the Sharî’at and refrain from the things which the Sharî’at dislikes, from the bid’ats.

If a person uncovers an abandoned, forgotten sunnat, he will get the thawâb of a hundred martyrs. Then, just imagine how much thawâb there is in resuscitating a fard or wâjib. Therefore, one should be careful about the ta’dîl-i arkân when performing namâz. In other words, at the rukû, at the sajda, at the qawma and at the jalsa, each limb should become motionless and remain so for a while; most of the savants of the Hanafî said that this was wâjib. Imâm-i Abû Yûsuf and Imâm-i Shâfi’î said that it was fard. The majority of Muslims have been neglecting this. A person who reveals this one deed will be given much more thawâb than that which is given to a hundred martyrs who have fought and given their lives in the way of Allah. This same rule applies to all the rules of the Sharî’at. That is, a person who teaches one of the halâls, harâms, makrûhs, fards, wâjibs and sunnats and has it obeyed will get the same amount of thawâb.