Ezekiel 3:4

⁴ And He saith unto me, `Son of man, go, enter in unto the house of Israel, and thou hast spoken with My words unto them.

Lip

'A lip' in general signifies doctrine.

In Isaiah 6:3, 7, this signifies the interior parts of a person and thus internal worship where adoration is grounded.

In Isaiah 37:29, this signifies the thought of the understanding

In Malachi 2:6, 7, this denotes doctrine grounded in charity.

² `Son of man, in the midst of the rebellious house thou art dwelling, that have eyes to see, and they have not seen; ears they have to hear, and they have not heard; for a rebellious house [are] they.