Ruling on reciting Qur’an for one who is sitting or reclining
Question

Is it permissible for me to recite Qur’an – and also dhikr – when I am sitting on a chair?
Praise be to Allah.It is permissible to recite Qur’an and remember Allah, may He be exalted, when sitting on a chair, or reclining, or lying on one’s side or back, and so on.
The fact that this is permissible is indicated by the report narrated by the Mother of the Believers ‘Aa’ishah (may Allah be pleased with her), who said: The Prophet (blessings and peace of Allah be upon him) used to recline in my lap when I was menstruating, then recite Qur’an. Narrated by al-Bukhaari (297) and Muslim (301).
Ibn Rajab said in Fath al-Baari (1/406):
This hadith indicates that it is permissible to recite Qur’an reclining, lying down, and on one’s side. That is included in the verse in which Allah, may He be exalted, says (interpretation of the meaning): {Who remember Allah while standing or sitting or [lying] on their sides} [Aal ‘Imraan 3:191]. End quote.
And Allah knows best.