“The former demoniac
Went away.
He began to proclaim
In the Decapolis towns
How much Jesus
Had done for him.
Everyone was amazed.”
καὶ ἀπῆλθεν καὶ ἤρξατο κηρύσσειν ἐν τῇ Δεκαπόλει ὅσα ἐποίησεν αὐτῷ ὁ Ἰησοῦς, καὶ πάντες ἐθαύμαζον.
There is something similar in Luke, chapter 8:39, while there is nothing like this in Matthew. Mark said that the former demoniac went away (καὶ ἀπῆλθεν). He then began to preach or proclaim (καὶ ἤρξατο κηρύσσειν) in the Decapolis area (ἐν τῇ Δεκαπόλει) how much Jesus had done for him (ὅσα ἐποίησεν αὐτῷ ὁ Ἰησοῦς). Thus, everyone there was amazed or marveled at this (καὶ πάντες ἐθαύμαζον). The Decapolis territory was a group of 10 gentile non-Jewish cities on the east bank of the Jordan River in present day Jordan and Syria that included the towns of Gerasa, Scythopolis, Hippos, Gadara, Pella, Philadelphia, Capitolias, Canatha, Raphana, and Damascus. Thus, this cured demoniac was the first Christian apostle to the gentiles.