Was reading (aneginōsken). Imperfect active descriptive, not periphrastic like the two preceding verbs (was returning and sitting). He was reading aloud as Philip “heard him reading” (ēkousen auton anaginōskontos), a common practice among orientals. He had probably purchased this roll of Isaiah in Jerusalem and was reading the lxx Greek text. See imperfect again in Act 8:32.