proof to my jewish friends that sarah was dead before Abraham remarried

Genesis 23 King James Version (KJV)

23 And Sarah was an hundred and seven and twenty years old: these were the years of the life of Sarah.

² And Sarah died in Kirjatharba; the same is Hebron in the land of Canaan: and Abraham came to mourn for Sarah, and to weep for her.
³ And Abraham stood up from before his dead, and spake unto the sons of Heth, saying,
⁴ I am a stranger and a sojourner with you: give me a possession of a buryingplace with you, that I may bury my dead out of my sight.
⁵ And the children of Heth answered Abraham, saying unto him,
⁶ Hear us, my lord: thou art a mighty prince among us: in the choice of our sepulchres bury thy dead; none of us shall withhold from thee his sepulchre, but that thou mayest bury thy dead.
⁷ And Abraham stood up, and bowed himself to the people of the land, even to the children of Heth.
⁸ And he communed with them, saying, If it be your mind that I should bury my dead out of my sight; hear me, and intreat for me to Ephron the son of Zohar,
⁹ That he may give me the cave of Machpelah, which he hath, which is in the end of his field; for as much money as it is worth he shall give it me for a possession of a buryingplace amongst you.
¹⁰ And Ephron dwelt among the children of Heth: and Ephron the Hittite answered Abraham in the audience of the children of Heth, even of all that went in at the gate of his city, saying,
¹¹ Nay, my lord, hear me: the field give I thee, and the cave that is therein, I give it thee; in the presence of the sons of my people give I it thee: bury thy dead.
¹² And Abraham bowed down himself before the people of the land.
¹³ And he spake unto Ephron in the audience of the people of the land, saying, But if thou wilt give it, I pray thee, hear me: I will give thee money for the field; take it of me, and I will bury my dead there.
¹⁴ And Ephron answered Abraham, saying unto him,
¹⁵ My lord, hearken unto me: the land is worth four hundred shekels of silver; what is that betwixt me and thee? bury therefore thy dead.
¹⁶ And Abraham hearkened unto Ephron; and Abraham weighed to Ephron the silver, which he had named in the audience of the sons of Heth, four hundred shekels of silver, current money with the merchant.
¹⁷ And the field of Ephron which was in Machpelah, which was before Mamre, the field, and the cave which was therein, and all the trees that were in the field, that were in all the borders round about, were made sure
¹⁸ Unto Abraham for a possession in the presence of the children of Heth, before all that went in at the gate of his city.
¹⁹ And after this, Abraham buried Sarah his wife in the cave of the field of Machpelah before Mamre: the same is Hebron in the land of Canaan.
²⁰ And the field, and the cave that is therein, were made sure unto Abraham for a possession of a buryingplace by the sons of Heth.

Genesis 25 King James Version (KJV)

25 Then again Abraham took a wife, and her name was Keturah.

² And she bare him Zimran, and Jokshan, and Medan, and Midian, and Ishbak, and Shuah.
³ And Jokshan begat Sheba, and Dedan. And the sons of Dedan were Asshurim, and Letushim, and Leummim.
⁴ And the sons of Midian; Ephah, and Epher, and Hanoch, and Abidah, and Eldaah. All these were the children of Keturah.
⁵ And Abraham gave all that he had unto Isaac.
⁶ But unto the sons of the concubines, which Abraham had, Abraham gave gifts, and sent them away from Isaac his son, while he yet lived, eastward, unto the east country.
⁷ And these are the days of the years of Abraham's life which he lived, an hundred threescore and fifteen years.
⁸ Then Abraham gave up the ghost, and died in a good old age, an old man, and full of years; and was gathered to his people.
⁹ And his sons Isaac and Ishmael buried him in the cave of Machpelah, in the field of Ephron the son of Zohar the Hittite, which is before Mamre;
¹⁰ The field which Abraham purchased of the sons of Heth: there was Abraham buried, and Sarah his wife.
¹¹ And it came to pass after the death of Abraham, that God blessed his son Isaac; and Isaac dwelt by the well Lahairoi.
¹² Now these are the generations of Ishmael, Abraham's son, whom Hagar the Egyptian, Sarah's handmaid, bare unto Abraham:
¹³ And these are the names of the sons of Ishmael, by their names, according to their generations: the firstborn of Ishmael, Nebajoth; and Kedar, and Adbeel, and Mibsam,
¹⁴ And Mishma, and Dumah, and Massa,
¹⁵ Hadar, and Tema, Jetur, Naphish, and Kedemah:
¹⁶ These are the sons of Ishmael, and these are their names, by their towns, and by their castles; twelve princes according to their nations.
¹⁷ And these are the years of the life of Ishmael, an hundred and thirty and seven years: and he gave up the ghost and died; and was gathered unto his people.
¹⁸ And they dwelt from Havilah unto Shur, that is before Egypt, as thou goest toward Assyria: and he died in the presence of all his brethren.
¹⁹ And these are the generations of Isaac, Abraham's son: Abraham begat Isaac:
²⁰ And Isaac was forty years old when he took Rebekah to wife, the daughter of Bethuel the Syrian of Padanaram, the sister to Laban the Syrian.
²¹ And Isaac intreated the Lord for his wife, because she was barren: and the Lord was intreated of him, and Rebekah his wife conceived.
²² And the children struggled together within her; and she said, If it be so, why am I thus? And she went to enquire of the Lord.
²³ And the Lord said unto her, Two nations are in thy womb, and two manner of people shall be separated from thy bowels; and the one people shall be stronger than the other people; and the elder shall serve the younger.
²⁴ And when her days to be delivered were fulfilled, behold, there were twins in her womb.
²⁵ And the first came out red, all over like an hairy garment; and they called his name Esau.
²⁶ And after that came his brother out, and his hand took hold on Esau's heel; and his name was called Jacob: and Isaac was threescore years old when she bare them.
²⁷ And the boys grew: and Esau was a cunning hunter, a man of the field; and Jacob was a plain man, dwelling in tents.
²⁸ And Isaac loved Esau, because he did eat of his venison: but Rebekah loved Jacob.
²⁹ And Jacob sod pottage: and Esau came from the field, and he was faint:
³⁰ And Esau said to Jacob, Feed me, I pray thee, with that same red pottage; for I am faint: therefore was his name called Edom.
³¹ And Jacob said, Sell me this day thy birthright.
³² And Esau said, Behold, I am at the point to die: and what profit shall this birthright do to me?
³³ And Jacob said, Swear to me this day; and he sware unto him: and he sold his birthright unto Jacob.
³⁴ Then Jacob gave Esau bread and pottage of lentiles; and he did eat and drink, and rose up, and went his way: thus Esau despised his birthright.

King James Version (KJV)