Ezekiel 3:17

¹⁷ that there is a word of Jehovah unto me, saying, `Son of man, a watchman I have given thee to the house of Israel, and thou hast heard from My mouth a word, and hast warned them from Me.

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.

⁷ For the priest's lips should keep knowledge, and they should seek the law at his mouth; for he is the messenger of Yahweh of Armies.