Question Summary:
Is it permissible to lay on your stomach?

Question Detail:

Is it permissible to lay on your stomach other than sleeping. For eg when one has a stomach ache or maybe just to read a book. 

Answer :

In the Name of Allah, the Most Gracious, the Most Merciful.
As-salāmu ‘alaykum wa-rahmatullāhi wa-barakātuh.
It is discouraged for one to lay on his/her stomach is due to the following Hadith of the Prophet (SallAllāhu ῾Alayhi Wasallam):
عَنْ أَبِي ذَرٍّ، قَالَ مَرَّ بِيَ النَّبِيُّ ـ صلى الله عليه وسلم ـ وَأَنَا مُضْطَجِعٌ عَلَى بَطْنِي فَرَكَضَنِي بِرِجْلِهِ وَقَالَ ‏ "‏ يَا جُنَيْدِبُ إِنَّمَا هَذِهِ ضِجْعَةُ أَهْلِ النَّارِ ‏"‏ ‏.‏
It was narrated that Abu Dharr said:
"The Prophet(ﷺ) passed by me and I was lying on my stomach. He nudged me with his foot and said: 'O Junaidib! This is how the people of Hell lie.'(Sunan Ibn Majah 3724)

The above mentioned hadith clearly mentions that for one to lie on his/her stomach is disliked by Allah Ta’ala, therefore, one should abstain from doing so.
 
And Allah Ta’āla Knows Best
Arshad Ali
Student Darul Iftaa
Trinidad
Checked and Approved by,
Mufti Ebrahim Desai.
http://www.daruliftaa.net/