'Lips' in the Bible

These people give me honour with their lips, but their heart is far from me.

But if he will not give ear to you, take with you one or two more, that by the lips of two or three witnesses every word may be made certain.

Have you any idea what these are saying? And Jesus said to them, Yes: have you not seen in the Writings, From the lips of children and babies at the breast you have made your praise complete?