In Psalms 149:3, 'the timbrel' signifies good, and 'the harp,' truth. This also signifies good and truth in harmony. (Arcana Coelestia 420)

'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.

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