en_obs-tn/content/22/01.md

his people

This could be translated as, “his people, the Israelites” or “his people, the Jews.” But only include the added information if it is not clearly understood who these people were.

400 years went by

Another way to say this would be, “400 years passed” or “there were 400 years.” 400 years had passed since the last Old Testament prophet, Malachi.

when he did not speak to them

That is, “during which God did not give any messages to the prophets for his people.”