The abstract noun "dictation" can be translated as a verb. See how similar words are translated in [Jeremiah 36:4](../36/04.md). Alternate translation: "while Jeremiah was speaking, Baruch wrote on it" (See: [[rc://en/ta/man/translate/figs-abstractnouns]])
This can be translated in active form. Alternate translation: "Furthermore, Jeremiah and Baruch added to this scroll many more words which were similar to the words that had been in the first scroll" (See: [[rc://en/ta/man/translate/figs-activepassive]])