Interestingly, the phrase "Promised Land" is not found anywhere in the King James Bible! That said, when God called Moses, through a burning bush, he promised to not only free his people but also give them the territory sojourned by their ancestors Abraham, Isaac and Jacob.
And I am coming down to deliver them out of the hand of the Egyptians, to bring them up out of that land . . . to a land flowing with milk and honey, to the place of the Canaanites and the Hittites and the Amorites and the Perizzites and the Hivites and the Jebusites (Exodus 3:8, HBFV).
The Lord, while instructing his people regarding the Passover, reiterated the above promise to them.
And it shall be when you have come to the land which the Lord will give you, according as He has promised that you shall keep this service (the Passover - Exodus 12:25).
Moses himself referenced a promised land in some of his speeches before the people.
Listen to them (God's laws, commandments and judgments) . . . and you will become a mighty nation and live in that rich and fertile land, just as the Lord, the God of our ancestors, has promised (Deuteronomy 6:3).
And you shall engrave upon them all the words of this law when you have passed over so that you may go in to the land . . . as the Lord God of your fathers has promised you (Deuteronomy 27:3, see also 9:23, 26 - 28).
An ancient pledge
The book of Genesis informs us the idea of a guaranteed inheritance originated with God making a covenant with the patriarch Abraham. He informed the father of the faithful, "I will give to you and to your descendants this land (Canaan) in which you are now a foreigner . . . (it) will belong to your descendants forever" (Genesis 17:8).
God told Abraham that he and his descendants would be given the area known as Canaan (the Promised Land). Because of Abraham's faith and obedience, he and his children would be given a permanently place to live as an inheritance! The New Testament reaffirmed this guarantee made by the Eternal when it stated the following.
By faith Abraham, being called of God to go out into the place which he would later receive for an inheritance, obeyed and went, not knowing where he was going. By faith he sojourned in the land of promise, like a foreigner, dwelling in tabernacles with Isaac and Jacob, the joint heirs of the same promise;
For he was waiting for the city with the foundations of which God is the Architect and Builder (Hebrews 11:8 - 10, HBFV).