Is drinking water is sunnat after food or not necessary to drink water after food?

In the name of Allāh, Most Gracious, Most Merciful

Assalāmu ῾alaykum wa Rahmatullāhi Wabarakātuh

Allamah Ibnul Qayyim رحمه الله  has mentioned that the habit of Nabi salallahu alayhi wasallam was that of not drinking immediately after eating as this is harmful to the digestion process. However, if there is a pressing need to drink immediately after that, then only drink enough to quench the thirst. One may then drink after some time elapses.

NOTE: This elapsed time is estimated to be 20-30 minutes.

ولم يكن من هَدْيه أن يشربَ على طعامه فيُفسده ... ويُكره شرب الماء عقيبَ الرياضة، والتعبِ، وعقيبَ الجِمَاع، وعقيبَ الطعامِ وقبله، وعقيبَ أكل الفاكهة، وإن كان الشربُ عقيبَ بعضِها أسهلَ مِن بعض، وعقب الحمَّام، وعند الانتباه من النوم، فهذا كُلُّهُ منافٍ لحفظ الصحة، ولا اعتبار بالعوائد، فإنها طبائع ثوانٍ.
(زاد المعاد,دار التقوى , ج3, ص114 )

And Allāh Ta῾āla Knows Best

Wassalāmu ῾alaykum 

Ml. Luqman Hansrot,
Student Dārul Iftā

Checked and Approved by:

Mufti Ebrahim Desai
Dārul Iftā