O Zion, that brings good tidings, get you up into the high mountain; O Jerusalem, that brings good tidings, lift up your voice with strength; lift it up, be not afraid; say unto the cities of Judah, Behold your God!
All Commentaries on Isaiah 40:9 Go To Isaiah 40
Cyril of Jerusalem
AD 386
For in the power of the Holy Spirit, by the will of the Father and the Son, Peter stood with the Eleven and, lifting up his voice (according to the text, “Lift up your voice with strength, you who bring good tidings to Jerusalem”), captured in the spiritual net of his words about three thousand souls. So great was the grace that worked in all the apostles together, that, out of the Jews … this great number believed, were baptized in the name of Christ and continued steadfast in the apostles’ doctrine and in the prayers.