Acts 8:38

And he commanded the chariot to stand still i.e. he ordered the chariot-driver to stop, and of course the whole retinue would see what took place, and they may certainly be regarded as the nucleus of a congregation to be established in Ethiopia. Tradition tells us that the eunuch laboured to evangelize his countrymen, and none were more likely to be influenced by his teaching than those who were present at his baptism and were, with him, witnesses of the way in which Philip was taken from them.

and they went down both into the water As was the custom among the Jews. Thus John baptized his followers in the Jordan.