Acts 8:35-36, 38

Then Philip spoke and beginning with this Scripture he preached Jesus to him [explaining that He is the promised Messiah and the source of salvation]. As they continued along the road, they came to some water; and the eunuch exclaimed, “Look! Water! What forbids me from being baptized?”

And he ordered that the chariot be stopped; and both Philip and the eunuch went down into the water, and Philip baptized him.