Charles Spurgeon Commentary Genesis 18:17-19

"And Jehovah said, Shall I hide from Abraham that which I do; seeing that Abraham had 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 Jehovah, to do righteousness and justice; to the end that Jehovah may bring upon Abraham that which he hath spoken of him." — Genesis 18:17-19 (ASV)

And the LORD said, Shall I hide from Abraham that thing which I do; seeing that Abraham shall surely become a great and mighty nation, and all the nations of the earth shall be blessed in him? For I know him, that he will command his children and his household after him, and they shall keep the way of the LORD, to do justice and judgment; that the LORD may bring upon Abraham that which he hath spoken of him.

Abraham is called "the friend of God." It was not merely that God was his Friend; that was blessedly true, and it was a great wonder of grace; but he was honoured to be called "the friend of God"—one with whom God could hold sweet converse, a man after his own heart, in whom he trusted, and to whom he revealed his secrets. I am afraid there are not many men of Abraham's sort in the world even now; but, wherever there is such a man, with whom God is familiar, he will be sure to be one who orders his household properly.

If the Lord is my Friend, and if I am indeed his friend, I will wish him to be respected by my children, and I will endeavor to dedicate my children to his service. I fear that the decline of family godliness, which is so sadly remarkable in these days, is the source of a great many of the crying sins of the age; the Church of God at large would have been more separate from the world if the little church in each man's house had been more carefully trained for God. If you want the Lord to confide in you, and to trust you with his secrets, you must see that he is able to say of you what he said of Abraham, he will command his children and his household after him.