What is the ruling on contemplating the essence of Allah Almighty, and what is the punishment for one who does so?

To know Allah and His Creator, one must know Him through what He has revealed about Himself in His Book and through the words of His Messenger concerning His Beautiful Names and Exalted Attributes, and through the signs of His greatness and Lordship that He has dispersed throughout the universe. No created being can comprehend the reality of the Creator's essence, as Allah the Almighty says: "And they encompass Him not in knowledge" (Quran 20:110) and "Vision perceives Him not" (Quran 6:103). And the Prophet, peace and blessings be upon him, said: "Ponder upon the favors (blessings) of Allah, but do not ponder upon Allah Himself." Therefore, the sound approach for a believer is to ponder upon Allah's attributes and signs. And whoever experiences whispers concerning pondering upon Allah's essence should seek refuge [in Allah] and say, "I believe in Allah."