'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.
(Odkazy: Arcana Coelestia 1284, Arcana Coelestia 1288)
