'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.

(Verweise: Arcana Coelestia 1284, Arcana Coelestia 1288)

'Being sent' means coming forth, (or going forth), in the internal sense, as in John 17:8. In similar manner, it is said of the holy of the spirit, that it was 'sent,' that is, it goes forth from the divine of the Lord, as in John 15:26, 16:5, 7.

So, too, the prophets were called 'the sent,' because the words which they spoke went forth from the holy of the spirit of the Lord.

'To be sent,' as in Genesis 37:13, signifies teaching.

(Verweise: Arcana Coelestia 2397; John 15:7)