ANSWER:

You are not obliged to rinse your mouth but it is recommended. 

We were at a masjid one day and had just finished eating before we came and so we drank water to rinse our mouths and were told that it’s not sufficient unless we rinse the mouth 3 times, making sure to spit each one out. What is the correct opinion about rinsing the mouth after eating to maintain wudhu

Prayer |