Inability to stand in prayer
3-1-2018 | IslamWeb
Question:
Assalaamu alaykum wa rahmatullaahi wa barakaatuhu. Respected Shaykhs, I just read your previous answer, No. 354958, today, but before that I was unaware of the ruling, and I will repeat those two prayers, Allah willing, but please answer the following. A short, quick reply by email will be needful, Allah willing.
Q: I sit and pray on a chair; I mostly use two chairs as I suffer from my heels. When I pray on two chairs, while keeping my legs straight in front of me on the second chair, I start the prayer while sitting, but when I sometimes pray on one chair, I just stand and say the opening Takbeer (saying: Allahu Akbar [Allah is the Greatest]) and pray the rest of the prayer while sitting down. Rarely, I do stand some seconds longer than the opening Takbeer. Having read your previous answer (No. 345262) on my question regarding standing, particularly in the third unit of prayer, I feel that I am not obliged to stand for the opening Takbeer, but i want to make sure whether I am right or not. If I am obliged to stand and say the opening Takbeer, then what about all previous prayers, whose number is unknown to me, and which are many, stretching from March 2017 till today. I have been doing so as I am unaware of a particular ruling on this specific question of mine. Please give a quick, short response by email, as I am worried after reading your fatwa that I received yesterday or today itself that if I have to repeat those two prayers, then what about the above situation of the two chairs and my being unaware of the specific ruling till I read it last night? I had no answer until then, and I recently referred back to the fatwa about standing in the third unit of prayer, and before and after that, I kept praying while sitting fully when on two chairs. This morning, I stood and then sat and stretched my legs in front of me on the second chair, and I felt no real Khushoo‘ (humble submissiveness) and was distracted by the placement of my legs in the front chair while engaged in prayer. Please advise on what is best when I pray alone and what is best when I pray in congregation, as I will most probably even distract others around me in prayer then. Please respond by email, today, with a short, quick response, if possible, as otherwise I will have to wait and will have to do what I did this Fajr, and your fatwa might say otherwise. May Allah reward you.
Answer:
All perfect praise be to Allah, the Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad 
is His slave and Messenger.
Our previous answers to you are very clear. If you can stand in some parts of the prayer, then you are obliged to stand to the extent of your ability and then sit down when you cannot continue praying while you are standing.
If you need to sit down from the beginning of the prayer because you cannot sit except in that manner and it is difficult for you to stand up and then sit down, then there is no harm on you, as the Shariah is easy and it makes things easy for those who are obliged to perform Islamic obligations. Allah exempted us from hardship and shackles out of His Favor and Mercy.
Whether you can pray on one chair or two chairs, you do what is more convenient for you and what enables you to perform the prayer as it should be performed.
If in the past you did not stand in the prayer while you were able to do so because you believed that it was not necessary for you do so, then you are not obliged to make up for the prayers which you performed in this manner according to the view of Shaykh Ibn Taymiyyah 
because of your ignorance about the ruling in this regard.
Allah knows best.