Everlasting

Genesis 17:7-8 ESV 

And I will establish my covenant between me and you and your offspring after you throughout their generations for an everlasting covenant, to be God to you and to your offspring after you. And I will give to you and to your offspring after you the land of your sojournings, all the land of Canaan, for an everlasting possession, and I will be their God.”

God is everlasting. If anyone would know what this means, it would be the everlasting one. When He says He will make an everlasting covenant, I suspect it would be everlasting as He is everlasting. 

Canaan belongs to Israel. God gave them the deed for the land and it is their birthright. God has given His word and it is written on the flesh and hearts of His people.  

Genesis 17:11-13

You shall be circumcised in the flesh of your foreskins, and it shall be a sign of the covenant between me and you. He who is eight days old among you shall be circumcised. Every male throughout your generations, whether born in your house or bought with your money from any foreigner who is not of your offspring, both he who is born in your house and he who is bought with your money, shall surely be circumcised. So shall my covenant be in your flesh an everlasting covenant.