A.T. Robertson Commentary Luke 1:14

"And thou shalt have joy and gladness; and many shall rejoice at his birth." — Luke 1:14 (ASV)

Gladness (αγαλλιασις). Only in the LXX and N.T. so far as known. A word for extreme exultation.

Rejoice (χαρησοντα). Second future passive indicative. The coming of a prophet will indeed be an occasion for rejoicing.