Was the entire Qur’an interpreted during the era of the Prophet, peace and blessings be upon him?

The entire Qur’an was not expounded during the time of the Prophet, peace and blessings be upon him. He only explained to them what was unclear, because the Companions were pure Arabs and the Qur’an was revealed in their language, so they did not need an explanation to understand it. However, the complete Qur’an was expounded in later times due to the mixing of languages resulting from the conquests, which necessitated the need to know its meanings. Thus, scholars wrote books of exegesis (tafsir).