“I shall make your (Isaac)’s descendants as numerous as the stars of heaven and I shall give them all these countries- and all nations shall bless themselves by your descendants’ (Gen26:4)
Isaac’s father had effectively become the father of covenantal faith, but it was never faith alone:
“(I shall do this) as a result of Abraham’s obedience; for he kept my charge, my commandments, my statutes and my laws” (following verse).
The Apostle Paul writing to Christians in Galatia said that they, like Isaac, were the children of promise (Gal4:28). But as outlined in an earlier post, Isaac’s half-brother Ishmael was also blessed by God yet excluded from the Abrahamic covenant. That is one of many indicators of the broader benign providence being outlined in “The Little Book of Providence”, a free PDF of which is available HERE