The Qur’an is the single greatest book on earth. It was revealed in the Arabic language. Allah (SWT) when explaining the same exact thing in a different part of the Qur’an uses different words when describing. What is the reason behind this?
The Quran is extremely eloquent. Allah SWT sometimes delivers the same message using different words. These words are always complimentary in meaning. Each time in the Qur'an, they work to give different perspectives in various contexts of the same important meaning.
Shaykh Mohammed Mana explains and further answers the question
The Qur'an is extremely eloquent. It was revealed in the Arabic language to a people that excelled in their eloquence of the Arabic language. It's a miracle from Allah (subhanahu wa ta'ala), the literary eloquence and the perfection of the Qur'an. Allah (subhanahu wa ta'ala) sometimes delivers the same message in different parts of the Qur'an using different words, and these words are always complementary in meaning. They often allow us to view the same topic or the same issue from a different perspective or from a different angle to get a different flavor of the same important meaning.