The "grave" of the "man of God" is the memory left by the righteous man of the way of his "dying" to sinful life by turning to the fulfillment of God's Will, His Commandments, the memory of the way of deliverance from error, of the way of achieving immunity to the temptations of sin.

"The Grave" is a symbol, of moral and spiritual corruption, of man's decay, of the environment of being among his kind, in which there is no understanding and fulfillment of God's Will.

"Grave" is also a symbol of man spiritually dead, unable to reason and fulfill God's Commandments. 

"The Grave" is also a symbol of a people spiritually empty, morally dead to perceive and fulfill the Will of God, in whose midst there is no "Light" of Truth, where there is no true spiritual life.

"Grave" is also a symbol of the past (present) sinful history of man, where his idols, leaders of the peoples, their ideas, deeds, etc., will fall into oblivion, into oblivion.