Ezekiel 3:8

⁸ `Lo, I have made thy face strong against their face, and thy forehead strong against their forehead.

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 And there doth come into me a spirit, when He hath spoken unto me, and it causeth me to stand on my feet, and I hear Him who is speaking unto me.