‘And Yahweh said, “Shall I hide from Abraham what am doing? Seeing that Abraham will surely become a great and mighty nation, and all the nations of the earth shall be blessed in him. For I have known him to the end that he may command his children and his household after him, that they may keep the way of Yahweh, to do righteousness and justice. To the end that Yahweh may bring on Abraham what he has said concerning him.” '
This is probably the time at which Abraham becomes aware that this is not just a messenger of Yahweh, but Yahweh Himself.
Nothing could more reveal the importance of Abraham in the purposes of God than this stated intention of Yahweh. Abraham is so involved in God's plan for the future of the world that he is deserving of knowing what God will do. God has, as it were, taken Abraham into partnership, albeit as a very junior partner. God does not hide His secrets from His prophets (Amos 3:7), and as Genesis 15 has made clear, Abram is a prophet.
The particular covenant of Genesis 12, rather than the wider covenant of Genesis 17, is in mind here as befits the previous mention of the special heir. This is a codicil to Genesis 18:14. It confirms that a great and mighty nation will arise from Abraham through Isaac, and that all the nations of the world will be blessed through Abraham, and his seed, through the chosen line. This latter promise is significantly only stated elsewhere in Genesis 12:3, which is pre-Ishmael, Genesis 22:18 where it is directly related to the incident with Isaac, and Genesis 26:4 where it is promised to Isaac. It is thus never directly related to the wider covenant of Genesis 17.
The covenants are clearly distinguished. This particular blessing is to come through the seed of Isaac, not of Ishmael. Thus, while Ishmael is to be blessed as Abraham's seed, God's purpose for the world will be achieved through Isaac's seed.
Incidentally this brings out how ancient the covenant in Genesis 17 is. Such promises would never have been conceded by later Israel.
“For I have known him ---”. The word to ‘know' means more than just intellectual knowledge. It is constantly used of personal relations between a man and a woman (Genesis 4:1 and often) and here it signifies that Yahweh has entered into a special relationship with Abraham. He has chosen him and set him apart in His purposes.
His purpose in setting Abraham apart is also stated. It is that he might so teach and order his family and family tribe to keep the way of Yahweh that they ‘do righteousness and justice'. It is this that will bring about the final blessing. Thus morality and ethics is set at the heart of the covenant with Abraham. But it is a morality set in what Yahweh Himself is, for it is ‘the way of Yahweh'. It is their personal response to Him and what He is that will bring the blessing to the whole world.
To ‘do righteousness' is to follow the covenant completely, to ‘do justice' is to deal with all failures to observe the covenant requirements. But the context of God's judgment on Sodom and Gomorrah brings out that these requirements are ethical and are demanded of all not just those in the covenant. The covenant stipulations are merely a mirror of what God requires from the world.
Now Yahweh reveals His full purpose to Abraham.