The ruling on one who prays the voluntary prayer sitting down while being able to stand

The question: The student at the Juf Scientific Institute, 'Abd al-Wahhab ibn 'Umar al-Murayhi, also asks: What is the ruling on one who prays the voluntary prayer while sitting, knowing that he is able to pray while standing, with evidence if possible?
The answer: It is established from the Messenger of Allah (peace and blessings be upon him) that he would sometimes pray his late-night voluntary prayer while sitting, and sometimes while standing (peace and blessings be upon him). This indicates the permissibility of performing the voluntary prayer while sitting; because Allah said: [Al-Ahzab: 21]; and because the voluntary prayer is encouraged and carries a great reward. So out of Allah's mercy, He made it broad, so that a person may pray whatever is easy for him, and may increase in voluntary prayers while sitting and standing. As for the obligatory prayer, it is not permissible to sit in it except for an excuse; because Allah said: [Al-Baqarah: 238], and the Prophet (peace and blessings be upon him) said to 'Imran ibn Husayn when he asked him about it: , and this is regarding the obligatory prayer. Al-Bukhari narrated this in his Sahih, and in a narration by al-Nasa'i: . This is the ruling for the obligatory prayer. It is obligatory for Muslims to pray it standing, if they are able, men and women. So if one is unable to do so due to illness, he prays sitting, or due to something resembling illness, such as a prisoner in a place with a low ceiling where he cannot stand and cannot leave, then he prays according to his condition [Al-Taghabun: 16]. If he is unable to sit, he prays on his side, and the right side is better. If he is unable to pray on his side, he prays lying on his back, gesturing with his head, and performing the prescribed remembrances. He performs the actions by intention: he says the takbir, opens the prayer, and recites al-Fatihah. He opens the prayer, seeks refuge, says the basmalah, seeks refuge, and recites al-Fatihah and whatever is easy with it. Then he says the takbir intending the bowing, while he is in his condition, lying on his back or on his side. He says the takbir intending the bowing and says: Subhan Rabbi al-'Azeem... Subhan Rabbi al-'Azeem... Subhanaka Allahumma Rabbana wa bihamdika, Allahumma ighfir li. Then he raises himself; if he is praying alone, he says: (Sami' Allahu li man hamidah) intending the raising from the bowing, while he is in his condition, lying on his back or on his side. Then he comes with the prescribed remembrance: Rabbana wa laka al-hamd... to the end of it. Then he says the takbir intending the prostration and says: Subhan Rabbi al-A'la... Subhan Rabbi al-A'la... to the end of it. He performs the words and the actions by intention. The words with their wording, and the remembrances likewise, and the supplications. He performs the actions by intention: the intention of bowing, the intention of prostration, the intention of sitting, like this. As for the voluntary prayer, its matter is broad, praise be to Allah. If he prays standing, it is better. If he prays sitting, it is half the reward of the one who stands, if he is able and prays sitting in the voluntary prayer, his prayer is valid, but he is on half the reward of the one who stands, as the Sunnah came from the Prophet (peace and blessings be upon him). Yes.