Surah Ar Rahman Tafseer

Then which of the blessings of your Lord will you both deny?

meaning, "O mankind and Jinn, which of the favors that Allah has given to you do you deny"

Mujahid and others said this, and it is apparent when one reads what comes after it. Meaning the favors that are obvious to you while you are surrounded by them, you cannot deny or reject them. So we say, just as the believers among the Jinns said, "O Allah! None of Your favors do we deny. All praise is due to You."

Ibn Abbas used to say, "Nay, our Lord!" meaning, "None of Your favors do we deny.