Happy Pentecost and Trinity Sunday!
The image link and the Greek Archdiocese both have a brief explanation of the feast’s icon.
Blessed art Thou, Christ our God,
Who didst make the fishermen wise by sending down upon them the Holy Spirit,
And through them didst draw the world into Thy net.
Lover of men, glory to Thee.
When the Most High came down and confused the tongues,
He divided the nations,
But when He distributed the tongues of fire,
He called all to unity.
And with one accord we glorify the All-Holy Spirit.