Luke 8:39
Return to thine own house, and shew how great things God hath done unto thee. And he went his way, and published throughout the whole city how great things Jesus had done unto him.
Cross-reference
Luke 2:17 describes shepherds spreading the news of Jesus' birth—another example of proclaiming what God has done.
In Luke 17:15-18, one leper returns to give thanks — here the man goes home to proclaim, both showing healed persons responding to God's work.
Psalm 66:16 also invites listeners to hear a personal testimony of what God has done for the speaker.
Psalm 126:3 directly declares 'The Lord has done great things for us', echoing the demoniac's proclamation of God's great work.
John 4:29 features the Samaritan woman testifying about Jesus, inviting others to 'come and see'—a parallel personal testimony.
Mark 5:18 is the parallel account where the delivered man begs to stay with Jesus, then is sent to tell his family.
Psalm 126:2 describes joyful proclamation among the nations that 'The Lord has done great things'—matching the demoniac's message.
Daniel 4:1-3 is Nebuchadnezzar's public testimony of God's signs and wonders after his restoration—similar to the demoniac's telling.
Daniel 4:34-37 records Nebuchadnezzar praising God for deliverance and declaring His sovereignty—parallel to the demoniac's testimony.
Mark 1:45 shows a healed leper spreading the news widely, but he disobeyed Jesus' command to keep silent, contrasting the demoniac's obedience.