Complex sentence: The prophet Isaiah was active in Jerusalem in the second half of the 8th century BCE; his followers probably wrote down or memorised his sayings and passed them on in turn to their own followers, together with their own additions and editorial comments.
Split into simpler sentences: The prophet Isaiah was active in Jerusalem in the second half of the 8th century BCE. His followers probably wrote down or memorised his sayings and passed them on in turn to their own followers, together with their own additions and editorial comments.