King James Version, Updated™

KJV:   1 And when Abram was ninety years old and nine, the LORD appeared to Abram, and said unto him, I am the Almighty God; walk before me, and be thou perfect.

KJVu: 1 When Abram was 99 years old, the LORD appeared to Abram, and said to him, "I am the Almighty God; walk before me, and be perfect.

KJV:   2 And I will make my covenant between me and thee, and will multiply thee exceedingly.

KJVu: 2 And I will make my covenant between me and you, and will multiply you exceedingly. "

KJV:   3 And Abram fell on his face : and God talked with him, saying,

KJVu: 3 And Abram fell on his face , and God talked with him, saying,

KJV:   4 As for me, behold, my covenant is with thee, and thou shalt be a father of many nations.

KJVu: 4 "As for me, behold, my covenant is with you, and you shall be a father of many nations.

KJV:   5 Neither shall thy name any more be called Abram, but thy name shall be Abraham ; for a father of many nations have I made thee.

KJVu: 5 Neither shall your name be Abram anymore, but your name shall be Abraham , for I have made youa father of many nations.

KJV:   6 And I will make thee exceeding fruitful, and I will make nations of thee, and kings shall come out of thee.

KJVu: 6 I will make you exceeding fruitful, and I will make nations from you, and kings shall come from you.

KJV:   7 And I will establish my covenant between me and thee and thy seed after thee in their generations for an everlasting covenant, to be a God unto thee, and to thy seed after thee.

KJVu: 7 And I will establish my covenant between me and you and your descendants after you in their generations for an everlasting covenant, to be God to you, and to your descendants after you.

KJV:   8 And I will give unto thee, and to thy seed after thee, the land wherein thou art a stranger, all the land of Canaan, for an everlasting possession ; and I will be their God.

KJVu: 8 And I will give to you, and to your descendants after you, the land wherein you are a stranger, all the land of Canaan, for an everlasting possession , and I will be their God. [lime-background]#""

KJV:   9 And God said unto Abraham, Thou shalt keep my covenant therefore, thou, and thy seed after thee in their generations.

KJVu: 9 Then God said to Abraham, "You shall keep my covenant therefore, you, and your descendants after you throughout their generations.

KJV:   10 This is my covenant, which ye shall keep, between me and you and thy seed after thee; Every man child among you shall be circumcised.

KJVu: 10 This is my covenant, which you shall keep, between me and YOU and your descendants after you. Every male child among YOU shall be circumcised.

KJV:   11 And ye shall circumcise the flesh of your foreskin ; and it shall be a token of the covenant betwixt me and you.

KJVu: 11 You shall circumcise the flesh of YOUR foreskin , and it shall be a sign of the covenant between me and YOU.

Notes:

KJV:   12 And he that is eight days old shall be circumcised among you, every man child in your generations, he that is born in the house, or bought with money of any stranger, which is not of thy seed.

KJVu: 12 He that is eight days old among YOU shall be circumcised, every male child in YOUR generations, he that is born in your house, or bought with money of any stranger, who is not of your descendants.

KJV:   13 He that is born in thy house, and he that is bought with thy money, must needs be circumcised : and my covenant shall be in your flesh for an everlasting covenant.

KJVu: 13 He that is born in your house, and he that is bought with your money, must be circumcised . My covenant shall be in YOUR flesh for an everlasting covenant.

KJV:   14 And the uncircumcised man child whose flesh of his foreskin is not circumcised, that soul shall be cut off from his people ; he hath broken my covenant.

KJVu: 14 And the uncircumcised male child whose flesh of his foreskin is not circumcised, that soul shall be cut off from his people . He has broken my covenant. "

KJV:   15 And God said unto Abraham, As for Sarai thy wife, thou shalt not call her name Sarai, but Sarah shall her name be.

KJVu: 15 And God said to Abraham, "As for Sarai your wife, you shall not call her name Sarai, but Sarah shall be her name.

KJV:   16 And I will bless her, and give thee a son also of her : yea, I will bless her, and she shall be a mother of nations; kings of people shall be of her.

KJVu: 16 And I will bless her, and give you a son by her . Indeed, I will bless her, and she shall be a mother of nations; kings of people shall come from her."

KJV:   17 Then Abraham fell upon his face, and laughed, and said in his heart, Shall a child be born unto him that is an hundred years old? and shall Sarah, that is ninety years old, bear?

KJVu: 17 Then Abraham fell on his face, and laughed, and said in his heart, "Shall a child be born to him that is 100 years old? And shall Sarah, that is 90 years old, give birth?"

KJV:   18 And Abraham said unto God, O that Ishmael might live before thee!

KJVu: 18 And Abraham said to God, "O that Ishmael might live before you!"

KJV:   19 And God said, Sarah thy wife shall bear thee a son indeed; and thou shalt call his name Isaac : and I will establish my covenant with him for an everlasting covenant, and with his seed after him.

KJVu: 19 And God said, "Sarah your wife shall bear you a son , and you shall call his name Isaac . I will establish my covenant with him for an everlasting covenant, and with his descendants after him.

KJV:   20 And as for Ishmael, I have heard thee: Behold, I have blessed him, and will make him fruitful, and will multiply him exceedingly ; twelve princes shall he beget, and I will make him a great nation.

KJVu: 20 As for Ishmael, I have heard you. Behold, I have blessed him, and will make him fruitful, and will multiply him exceedingly . He shall father twelve princes, and I will make him a great nation.

KJV:   21 But my covenant will I establish with Isaac, which Sarah shall bear unto thee at this set time in the next year.

KJVu: 21 But I will establish my covenant with Isaac, whom Sarah shall bear to you at this set time next year. "

KJV:   22 And he left off talking with him, and God went up from Abraham.

KJVu: 22 When he had finished talking with him, God went up from Abraham.

KJV:   23 And Abraham took Ishmael his son, and all that were born in his house, and all that were bought with his money, every male among the men of Abraham’s house ; and circumcised the flesh of their foreskin in the selfsame day, as God had said unto him.

KJVu: 23 Then Abraham took Ishmael his son, and all that were born in his house, and all that were bought with his money, every male among the men of Abraham’s house , and circumcised the flesh of their foreskin in the very same day, as God had said to him.

KJV:   24 And Abraham was ninety years old and nine, when he was circumcised in the flesh of his foreskin.

KJVu: 24 Abraham was 99 years old when he was circumcised in the flesh of his foreskin.

KJV:   25 And Ishmael his son was thirteen years old, when he was circumcised in the flesh of his foreskin.

KJVu: 25 And Ishmael his son was 13 years old, when he was circumcised in the flesh of his foreskin.

KJV:   26 In the selfsame day was Abraham circumcised, and Ishmael his son.

KJVu: 26 In the very same day Abraham and Ishmael his son were circumcised.

KJV:   27 And all the men of his house, born in the house, and bought with money of the stranger, were circumcised with him.

KJVu: 27 And all the men of his house, born in the house, and bought with money from a stranger, were circumcised with him.

Notes: Many translaions changed "stranger" to "foreigner" based on Strong’s H1121 (Brown-Driver-Briggs 7.a.). This change did not add to the understanding of the verse, so I opted to leave it as "stranger."