(6) It is obligatory that the person prays standing. This is a pillar (rukn) except for:
(i) The one who is praying the Fear Prayer or during severe fighting. In these circumstances it is permissible for him to pray whilst riding.
(ii) Also the one who is ill and the one who is unable to stand, he should pray sitting if he is able, or if not then whilst lying down.
(iii) Also the person praying Optional (Nafl) Prayer, he may pray whilst riding or whilst sitting if he wishes, and in this case he should perform rukoo' (bowing) and sujood (prostration) by lowering his head and likewise the sick. He should lower his head further for the prostration than for the bowing.
(7) It is not permissible for the person praying sitting to place something raised upon the ground to prostrate upon. Rather he should only make the movement for his prostration lower than that for his bowing, as we have already mentioned, this is what he does if he is unable to directly place his head upon the ground.
PRAYER ON A SHIP OR AIRPLANE
(8) It is permissible to pray the Obligatory Prayer upon a ship, and likewise in an airplane.
(9) A person may pray sitting in either of them if he fears that he will fall over.
(10) In the case of old age or bodily weakness, it is allowed for him during the standing to support himself against a pillar or with a stick.
(11) It is permissible to pray the voluntary Prayer during the night standing or even sitting without an excuse, and he can combine both of these. So he may pray and recite whilst sitting, and then shortly before the rukoo' he may stand and recite the few aayahs that remain for him whilst standing. Then he bows and prostrates, and then he does the same in the second rak'ah.
(12) If he prays sitting, he sits with his legs crossed, or in any manner of sitting that is comfortable for him.
PRAYER WHILST WEARING SHOES
(13) It is allowed for him to stand in Prayer barefooted, just as it is allowed for him to pray whilst wearing shoes.
(14) What is better is that he sometimes prays barefooted and sometimes prays wearing shoes, doing what is easy for him. So he should not force himself to wear them for the Prayer nor force himself to remove them. Rather if he happens to be barefooted he should pray barefooted, and if he is wearing shoes he should pray whilst wearing the shoes, unless a situation requires otherwise.
(15) If he does remove his shoes then he should not place them on his right-hand side, rather he should place them to his left as long as there is nobody praying to his left. Otherwise he should place them between his feet. This order is authentically reported from the Prophet (peace and blessing be upon him).
PRAYING WHILST STANDING UPON THE PULPIT (MINBAR)
(16) It is allowed for the Imaam to pray upon an elevated place, such as the minbar - for the purpose of teaching the people. He stands upon it and says the takbeer and recites and bows upon it.
Then he steps backwards in order to perform the prostrations on the ground at the foot of the pulpit. Then he can return to it and do in the second rak'ah the same as that which he did in the first.
The pillar (rukn) is that which is essential for completion of the affair that it falls within, being such that its absence necessitates that the action depending upon it is nullified. An example is the bowing (rukoo') in the Prayer - it is a pillar of it, and if it is absent then the Prayer is nullified.
The condition (shart) is like the pillar (rukn) except that it is something outside the action that is dependant upon it. An example is the ablution (wudoo) for the Prayer. Prayer is not correct without it.
The obligation (waajib) is that which has an established command in the Book or the Sunnah, but there is no proof that it is a pillar (rukn) or a condition (shart). One who carries it out is rewarded, and one who leaves it without valid excuse is punished. Just like it is the fard (obligation) and making a difference between the fard and the waajib is a newly invented use of terminology for which there is no proof.