17:18 And Abraham said, O that Ishmael might live before thee! - This he speaks nor as desiring that Ishmael might be preferred before the son he should have by Sarah, but as dreading lest he should be forsaken of God, he puts up this petition on his behalf. The great thing we should desire of God, for our children, is, that they may live before him, that is, that they may be kept in covenant with him, and may have grace to walk before him in their uprightness. God's answer to this prayer, is an answer of peace. Abraham could not say he sought God's face in vain.

Genesis 17:18 Parallel Commentaries

The Power of God
The next attribute is God's power. Job 9:19. If I speak of strength, lo, he is strong.' In this chapter is a magnificent description of God's power. Lo, he is strong.' The Hebrew word for strong signifies a conquering, prevailing strength. He is strong.' The superlative degree is intended here; viz., He is most strong. He is called El-shaddai, God almighty. Gen 17:7. His almightiness lies in this, that he can do whatever is feasible. Divines distinguish between authority and power. God has both. …
Thomas Watson—A Body of Divinity

Covenanting Performed in Former Ages with Approbation from Above.
That the Lord gave special token of his approbation of the exercise of Covenanting, it belongs to this place to show. His approval of the duty was seen when he unfolded the promises of the Everlasting Covenant to his people, while they endeavoured to perform it; and his approval thereof is continually seen in his fulfilment to them of these promises. The special manifestations of his regard, made to them while attending to the service before him, belonged to one or other, or both, of those exhibitions …
John Cunningham—The Ordinance of Covenanting

Confessing Christ an Indispensable Duty.
"--If we deny him, he also will deny us." This is predicated of Christ; and looks forward to the day when all mankind will stand before him as their judge. Denying Christ is here declared to be a mortal sin. Those found guilty of it will hear that sentence--"Depart ye cursed!" But this is to be understood only of a persevering denial of him. Those who turn by a timely repentance, will find mercy. This is true of every sin. But repentance may be too late. It must antecede death, or it will be of …
Andrew Lee et al—Sermons on Various Important Subjects