Luke
Acts 8:36BSB·traditional attribution

As they traveled along the road and came to some water, the eunuch said, “Look, here is water! What is there to prevent me from being baptized?”

John Calvin Reformed @genevareformer

36. What letteth me? The eunuch’s baptism ensueth now, whence we gather how greatly he profited in a small time, seeing he offereth himself willingly to give Christ his name. For it must needs be that faith was after a sort ripe in his heart, seeing that he brake out into external profession with such desire.

Matthew Henry Presbyterian @wholebiblehenry

We have here the story of the conversion of an Ethiopian eunuch to the faith of Christ, by whom, we have reason to think, the knowledge of Christ was sent into that country where he lived, and that scripture fulfilled, Ethiopia shall soon stretch out her hands (one of the first of the nations) unto God, Psa 68:31. I.

Commenting on Acts 8:26-40

John Gill Reformed Baptist @doctorgill

And Philip said, if thou believest with all thine heart, thou mayest,.... Intimating, that if he did not believe, he had no right to that ordinance; though he was a proselyte to the Jewish religion, a serious and devout man, and was employed in a religious way, when Philip came up to him, and was very desirous of being instructed in the knowledge of divine...