Charles Ellicott Commentary Acts 8:28

"and he was returning and sitting in his chariot, and was reading the prophet Isaiah." — Acts 8:28 (ASV)

Sitting in his chariot read Isaiah the prophet.—After the manner of most Eastern nations, to whom silent reading is almost unknown, the eunuch was reading aloud. Philip heard him, and so gained an opening for conversation.

Was the scroll of Isaiah a newly found treasure? Had he bought the manuscript in Jerusalem, and was he reading the wonderful utterances for the first time? The whole narrative implies that he was reading the Septuagint version.