prayer

STANDINGProphet sallallaahu 'alaihi wasallam did fard or sunnah prayers stand as fulfilling God's command in Sura. Al Baqarah: 238. When traveling, he did pray sunnah at the top of his vehicle. He taught his people to perform prayers khauf on foot or driving.

 

Fasting

Fasting literally means holding (Ruling). when he said a silent shaum. when a restrained eaters could also say he shaum and so on.
shaum later this term became more specific meaning. the hold of everything that has been determined, at any given time and are conducted by a certain.
Ramadan fasting is not mandatory except by consensus. when in addition to Ramadan fasting becomes mandatory, then it is because something is causing the obligatory fasting.such nadzar and others. argument is a hadith the Prophet Muhammad when asked by the a'rabi. SAW in his words: and fasting Ramadan. asked the a'rabi: is it mandatory for me other than the month ramadan? Prophet replied: no. unless you want to fast sunnah. (Narratives of Abu Hurairah, narrated by bukhari in chapter shaum 1899)

the meaning of sincerity

sincere to Allah Subhanahu wata'ala meaning a person intends by his worship to her taqarrub (closer) to Allah Subhanahu wata'ala and get keridhaanNya.
If a slave wanted something else through worship, then here need to be specified later based on the following classifications: