Mark 5:19-20

19Jesus did not let him [come], but [instead] He said to him, “Go home to your family and tell them all the great things that the Lord has done for you, and how He has had mercy on you.”

20So 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.