Gevurot Meyruach Hakodesh 8:36-39

And as they were going along the derech, they came upon some mayim and the eunuch says, Hinei, mayim! What prevents me from being given Moshiachʼs tevilah of teshuva in the mikveh mayim? [And Philippos said, If you have emunah b'chol levavcha, it is mutar. And he answered, saying, Ani ma'amin ki Rebbe Melech HaMoshiach Yehoshua Ben HaElohim hu.] And he commanded the chariot to stop and both went down into the mikveh mayim, both Philippos and the eunuch, and Philippos gave him Moshiachʼs tevilah of teshuva in the mikveh mayim. And when they came up from the mikveh mayim, the Ruach Hakodesh of HASHEM took Philippos away, and the eunuch did not see him any longer, but was going on his way with lev same'ach.