On the desert road to Gaza, Philip explains Isaiah's words to an Ethiopian official reading in his chariot, and baptizes him in water by the road.
Acts 8:38–39World English Bible
38He commanded the chariot to stand still, and they both went down into the water, both Philip and the eunuch, and he baptized him.39When they came up out of the water, the Spirit of the Lord caught Philip away, and the eunuch didn’t see him any more, for he went on his way rejoicing.