ANSWER:

You must at least move your tongue. Without it, this would be like intrusive thoughts that have no impact or value. 

In my little knowledge I Know, in Islam, it is said that when we will do zikr, there should be movement of the lips. But when friends are sitting together or walking on the road or while sleeping at night sometimes is not possible to movement of the lips. So, if this kinds of situation,we do zikr without moving lips it will be valid ? May Allah bless you Sheikh.

Prayer |