The meaning of the King
The King is one of the Beautiful Names of Allah, and it has been mentioned five times in the Holy Quran as an attribute of Allah. Although it has also been mentioned to refer to the kings of the earth such as Saul in Surat Albaqarah Aya (247), and the king of Egypt in Surat Yusuf Aya (43), but Allah has no equal in His Names and attributes, He is perfect in His beautiful Names and Sublime attributes, as nothing of His creation resembles Him, nor is anything like Him.
Allah is the King of the worldly life and the Hereafter, no one shares His kingdom as mentioned in Aya (111) of Surat Alisraa {And Say praise be to Allah, the One who has not taken a son and has not had a partner in the kingdom, and has not had a protector out of weakness, and Magnify Him with all magnification}, so Allah is the only One who manages the affairs of His creation as He wills, and His decree is absolute, as when He decrees a matter, He only says to it Be, and it comes to be as He has stated in many verses of the Holy Quran, so He gives the kingdom to whom He wills, and takes it away from whom He wills.
Allah's kingdom is eternal and will never perish for He is the Ever-Living, the One who does not die, unlike the kingdom of His creation which perishes and they themselves perish. On the day of resurrection, there will be no king but Allah, as Allah says in Aya (16) of Surat Ghafir {The day they will come forth, nothing of them is hidden from Allah, To whom belongs the kingdom today?, to Allah, the One, the Oft-Omnipotent}, so all people will come forth from the graves on the day of resurrection, and nothing of them will be hidden from Allah, then Allah will say "To whom belongs the kingdom today?", so no one will answer Allah because all creatures are dead then He will answer Himself saying "To Allah, the One, the Oft-Omnipotent", and Abu Hurayrah narrated that the Prophet Muhammad (PBUH) said: "On the day of resurrection, Allah will hold the whole earth and fold the heaven with His Right Hand, then He will say ''I am the King, where are the kings of the earth?" (Sahih Albukhari 7382), and in another narration of Abdullah bin Umar, Allah's Messenger (PBUH) said: "Allah, the Exalted and Glorious, will fold the Heavens on the day of resurrection, and then He will place them on His right Hand and say I am the King, Where are the haughty, and Where are the proud?, then He will fold the earth on His left Hand and say I am the King, Where are the haughty, and Where are the proud?" (Sahih Muslim 2788).