In Luke 1:67-79 we find that shortly after Zechariah confirmed his son’s name (John the Baptist) he was filled with the Holy Spirit and then he spoke this prophetic message (v 67):
68 Praise the Lord, the God of Israel, because he has visited and redeemed his people.
69He has sent us a mighty Savior from the royal line of his servant David, 70 just as he promised through his holy prophets long ago. 71 Now we will be saved from our enemies and from all who hate us. He has been merciful to our ancestors by remembering his sacred covenant—73 the covenant he swore with an oath to our ancestor Abraham. 74 We have been rescued from our enemies so we can serve God without fear, 75 in holiness and righteousness
for as long as we live. 76 “And you, my little son, will be called the prophet of the Most High, because you will prepare the way for the Lord. 77 You will tell his people how to find salvation through forgiveness of their sins. 78 Because of God’s tender mercy, the morning light from heaven is about to break upon us, 79 to give light to those who sit in darkness and in the shadow of death, and to guide us to the path of peace.”
Outside of this beautiful prophetic message regarding his son’s would be life; the mere fact that Zechariah was verbally declaring a prophecy was a miracle all by itself. You can read about that tea in Luke 1:11-23.
In a nut shell, Zechariah was muted because after his prayer for a son was answer and Gabriel delivered the good news that God was going to bless him with a son; he failed to believe him.
This prophetic message was not only a conduit to praise God for the great work his son would do in his life, but to me it also represented God’s mercy to restore and reconcile Zechariah from his previous disbelief!