TSK
Treasury of Scripture Knowledge references in NET.
Abraham took his son Ishmael and every male in his household(whether born in his house or bought with money) and circumcised them on that very same day, just as God had told him to do.
and said,“‘I solemnly swear by my own name,’ decrees the LORD,‘that because you have done this and have not withheld your son, your only son,
Praise the LORD! How blessed is the one who obeys the LORD, who takes great delight in keeping his commands.
So anyone who breaks one of the least of these commands and teaches others to do so will be called least in the kingdom of heaven, but whoever obeys them and teaches others to do so will be called great in the kingdom of heaven.
So then, dear brothers and sisters, be firm. Do not be moved! Always be outstanding in the work of the Lord, knowing that your labor is not in vain in the Lord.
By faith Abraham obeyed when he was called to go out to a place he would later receive as an inheritance, and he went out without understanding where he was going.