Mark 5:20

So he [obeyed and] went away and began to publicly proclaim in Decapolis [the region of the ten Hellenistic cities] all the great things that Jesus had done for him; and all the people were astonished.

Matthew 4:25

Large crowds followed Him from Galilee and the Decapolis and Jerusalem and Judea and the other side of the Jordan.

Mark 7:31

Soon after this Jesus left the region of Tyre, and passed through Sidon to the Sea of Galilee, through the region of Decapolis [the ten Hellenistic cities].

Treasury of Scripture Knowledge

Summary

And he departed, and began to publish in Decapolis how great things Jesus had done for him: and all men did marvel.

Bible References

Decapolis

Mark 7:31
Soon after this Jesus left the region of Tyre, and passed through Sidon to the Sea of Galilee, through the region of Decapolis [the ten Hellenistic cities].
Matthew 4:25
Large crowds followed Him from Galilee and the Decapolis and Jerusalem and Judea and the other side of the Jordan.