'Key' in the Bible

They waited until they became anxious; but behold, he did not open the doors of the roof chamber. Therefore they took the key and opened them, and behold, their master had fallen to the floor dead.

“Then I will set the key of the house of David on his shoulder,When he opens no one will shut,When he shuts no one will open.

Woe to you lawyers! For you have taken away the key of knowledge; you yourselves did not enter, and you hindered those who were entering.”

“And to the angel of the church in Philadelphia write:He who is holy, who is true, who has the key of David, who opens and no one will shut, and who shuts and no one opens, says this:

Then the fifth angel sounded, and I saw a star from heaven which had fallen to the earth; and the key of the bottomless pit was given to him.

Then I saw an angel coming down from heaven, holding the key of the abyss and a great chain in his hand.