Prayer guide
Conditions, Pillars, and Wajibs of Salah
The pre-conditions that must be in place before the prayer begins, the pillars (arkan) without which it is invalid, and the obligatory acts (wajibat) which must be completed but whose forgetting can be repaired with sujud as-sahw.
The Conditions Before the Prayer
Eight conditions must be in place before takbir al-ihram: (1) the entry of the time — praying before the time begins is invalid; (2) purity from minor and major hadath (i.e. wudu / ghusl); (3) purity of clothing, body, and place of prayer from najasah; (4) covering of the awrah — the navel-to-knee for men, the whole body except face and hands for women; (5) facing the qiblah, except in genuine fear or when riding a mount on a journey; (6) intention (niyyah) in the heart for which prayer is being prayed; (7) Islam; (8) reaching the age of distinction (tamyiz, around 7) — children are commanded to pray at 7 and disciplined for missing at 10 (Abu Dawud 495).
The Pillars (Arkan)
The arkan are acts without which the prayer is invalid even if forgotten: (1) standing if able (qiyam); (2) the opening takbir (takbir al-ihram); (3) reciting Surah al-Fatihah in every rak'ah; (4) ruku' (bowing) with tranquility; (5) rising from ruku' until standing straight; (6) sujud (prostration) on the seven body parts — forehead with nose, two hands, two knees, two feet — with tranquility; (7) sitting between the two sujuds; (8) the final tashahhud; (9) sending salawat upon the Prophet ﷺ in the final tashahhud (per the dominant view); (10) the final salam to right and left; (11) tranquility (tuma'ninah) in every position; (12) the order of these acts. (Compiled from Bukhari, Muslim, and the hadith of 'the man who prayed badly' — Bukhari 6251.)
The Wajibs
The wajibat are obligatory but, if forgotten, are repaired by sujud as-sahw rather than invalidating the prayer: the takbirs between positions (other than takbir al-ihram), the tasbih in ruku' and sujud (Subhana rabbiya-l-'azim / al-a'la), 'Sami'a-llahu liman hamidah' said by the imam when rising, 'Rabbana wa laka-l-hamd' said when rising, the first tashahhud and sitting for it, the dhikr between the two sujuds (Rabbi-ghfir li). Forgetting one of these requires sujud as-sahw — two prostrations of forgetfulness, typically before the final salam.
The Hadith of the Man Who Prayed Badly
A man entered the masjid and prayed; then he came to the Prophet ﷺ. The Prophet ﷺ said: 'Go back and pray, for you have not prayed.' He prayed again as before, came again, and the Prophet ﷺ repeated his instruction. The third time the man said: 'By the One who sent you with truth, I cannot do it better. Teach me.' The Prophet ﷺ said: 'When you stand for the prayer, say takbir, then recite what you can of the Qur'an, then bow until you are at rest in your bowing, then rise until you stand upright, then prostrate until you are at rest in your prostration, then rise until you are at rest in your sitting, then prostrate again until you are at rest — and do that in your whole prayer.' (Bukhari 757, Muslim 397). The hadith establishes tuma'ninah — calm settledness — as a pillar of salah.