Abraham lived in the land of Chaldea, not far from Babylon. He was a descendant of Shem and, with all his family, preserved true faith in God. He was wealthy, having an abundance of cattle, silver, gold, and many servants, but he had no children and grieved over this.
God chose the righteous Abraham to preserve the true faith, through his offspring, for all mankind. In order to protect him and his offspring from the pagan people related to him, because the pagans among his relatives could more easily teach them idolatry, God appeared to Abraham and said, "Get thee out of thy country, and from thy kindred, and from thy father’s house, unto a land that I will show thee: And I will make of thee a great nation, and I will bless thee, and make thy name great...and in thee shall all families (peoples) of the earth be blessed" (Gen 12:1-2). God promised Abraham that, in time, from his offspring there should be born the Saviour of the world, promised to the first men, Who should bless all peoples of the earth.
Abraham was seventy-five years old at that time. He obeyed the Lord, took his wife Sarah, his cousin Lot, all the possessions they had acquired, and all their servants, and moved into the land which the Lord showed him. This land was called Canaan and was very fertile. At that time the Canaanites lived there. They were one of the most wicked of all peoples. The Canaanites were the offspring of Canaan, the son of Ham. Here the Lord appeared to Abraham anew and said: "For all the land that thou seest, to thee will I give it, and to thy seed for ever" (Gen. 13:15). Abraham built an altar and offered God a sacrifice of thanksgiving.
After this, the land of Canaan began to be called the Promised Land, since God promised to give it to Abraham and his offspring. Now it is called Palestine. This land is on the eastern shore of the Mediterranean Sea and the Jordan River flows down through its center.
When the flocks of Abraham and Lot began to grow plentiful, there was no longer enough room for them to remain together, and their shepherds began to argue with each other; then they decided to separate on friendly terms.
Abraham said to Lot "Let there be no strife, I pray thee, between me and thee...for we are brethren. Is not the whole land before thee? Separate thyself, I pray thee, from me...if thou depart to the right hand, then I will go the left" (Gen. 13:8-10).
Lot chose for himself the valley of the Jordan and settled in Sodom. Abraham remained in the land of Canaan and settled near Hebron, at the woods of Mamre. There, near the oak of Mamre, he set up his tent and built an altar to the Lord. This oak of Mamre is still alive in Palestine near the city of Hebron.
A short while after Lot had settled in Sodom, the neighboring King of Elam attacked Sodom, looted the city, took the people into captivity and seized their possessions. Among the captives was Lot. Abraham when he learned of this, immediately gathered his servants together (318 men), called his neighbors to help, overtook the enemy, attacked him, and seized his loot.
When Abraham returned, he met solemnly with Melchizedek, who was a priest of the Most-high God and King of Salem. He offered bread and wine as a gift to Abraham and blessed him.
Nothing is known concerning Melchizedek, his background, and his death. The name Melchizedek means king of righteousness, and the word Salem means peace. Melchizedek was a prototype of Jesus Christ. Just as Melchizedek was at the same time priest and king, so Jesus Christ is High Priest and King. Just as neither the beginning nor the end of the life of Melchizedek is told, he, as it were, lives forever. So also Christ is eternal God, King and High Priest; we call Jesus Christ the High Priest forever according to the order of Melchizedek. And just as our Lord Jesus Christ gave us, in the form of bread and wine, His Body and Blood, that is, Holy Communion, so also Melchizedek, foreshadowing the Saviour, offered Abraham bread and wine and, since he was older, blessed Abraham. Abraham accepted the blessing of Melchizedek with reverence and gave him the tenth part of his spoils.
Note: See Genesis, chaps. 12,14,15,16,17.
(from: The Law of God by Fr. Seraphim Slobodskoy)