Midrash sa Genesis 38:5: Bereshit Rabbah

“And her name was Ketura” – Rav said: This is Hagar. Rabbi Neḥemya said to him: ‘But is it not written “[Abraham took] another [vayosef]”?’ He said to him: ‘[That means only that] he married her on the basis of a divine command, just as it says: “The Lord continued [vayosef] speaking to me again, saying”’ (Isaiah 8:5). He said to him: ‘But is it not written “and her name was Ketura”?’ He said to him: ‘That is because she was perfumed [mekuteret] with mitzvot and good deeds.’ [He said to him:] But is it not written: “And to the sons of the concubines¹²Plural. If Hagar and Ketura were one and the same, Abraham would have had only one concubine. of Abraham [Abraham gave gifts and sent them away from Isaac his son, while he was still alive…]”?’ (Genesis 25:6). He said to him: ‘Pilagsham¹³The omission of the yud intimates that the word could be interpreted as a single concubine. is written. “While he was still alive [ḥai]” – [this alludes to Hagar] the one who had sat by the well and said to the One who lives [ḥai] forever: See my misery.’
Rabbi Berekhya said: Even though it says: “She [Hagar] went off and wandered in the wilderness…” (Genesis 21:14), lest you say that perhaps some person was suspected [of becoming immorally involved] with her, the verse states: “And her name was Ketura” – from the word ‘bound up’ [ketar]; she was like one who seals a treasure and takes it out bound and sealed.¹⁴Her name indicates that she was chaste after leaving Abraham.
Bar Kappara said: Additions [tosafto] that are granted by the Holy One blessed be He are even greater than the original item. Cain was the original son [of Eve], and Abel, because he was considered an addition, as it is written: “She continued [vatosef] giving birth…[to Abel]” (Genesis 4:2) – he was born with his two twin sisters.¹⁵Whereas Cain was born with just one twin sister (see Bereshit Rabba 22:2).
Joseph was the original son [of Rachel], and Benjamin, because addition is written in his regard,¹⁶See Genesis 30:24. he produced ten children, as it is written: “And the sons of Benjamin: Bela, and Bekher…” (Genesis 46:21).
Er was the original son [of Judah], and Shela, because an expression of addition is used for him,¹⁷See Genesis 38:5. he produced ten courts. That is what is written in Chronicles: “The sons of Shela son of Judah: Er, father¹⁸The term father in this passage refers to the head of a court. of Lekha; and Lada father of Maresha; and the families of the house of the craft of fine linen, of the house of Ashbe’a...” (I Chronicles 4:21–23).
Job’s age was originally¹⁹Before he began to suffer from his afflictions. only seventy years, and one hundred and forty years were added to his life, as it is written: “After this, Job lived for one hundred and forty years” (Job 42:16).
Hezekiah’s original reign²⁰Before being reprimanded by Isaiah and praying for forgiveness (Isaiah 38:1–3). was only fourteen years, but fifteen years were added to it, as it is stated: “Behold, I am adding fifteen years to your days” (Isaiah 38:5).
Ishmael was the original son, and the sons of Ketura, because an expression of addition is used regarding them²¹Genesis 25:1. [the verse tells us] “She bore him Zimran…” (Genesis 25:2).²²The verse goes on to list six children.

“And turned to an Adulamite man, and his name was Ḥira” – the Rabbis say: Ḥira is Ḥiram who was in the days of David, as it is stated: “For Ḥiram had been David’s friend all the days” (I Kings 5:15) – this man was accustomed to being a friend of this tribe. Rabbi Yehuda ben Rabbi Simon said: Ḥiram was someone else. According to the opinion of the Rabbis, he lived close to one thousand two hundred years; according to the opinion of Rabbi Yehuda [ben Rabbi Simon], he lived close to five hundred years.²²Both opinions agree that Hiram was the prince of Tyre who was addressed by the prophet Ezekiel (Ezekiel 28:2) almost five hundred years after the time of David (see Yalkut Shimoni, Va’era 180) The debate is whether Ḥiram was also the same person as the Ḥira in the time of Judah, five hundred or so years before David.
“There Judah saw the daughter of a certain Canaanite whose name was Shua, and he married her and cohabited with her” (Genesis 38:2).
“There Judah saw the daughter of a certain Canaanite whose name was Shua” – the daughter²³The Hebrew text has the word son, rather than daughter, but many suggest that the text should say daughter (see, e.g., Etz Yosef). of a merchant,²⁴This opinion interprets kenaani, generally translated as Canaanite, to mean merchant, which is in fact how the term is used in some places in Bible (see, e.g., Isaiah 23:8). Accordingly, Judah followed the family tradition of not marrying Canaanites. the shining light of his place.
“She conceived, and she bore a son; he called his name Er” (Genesis 38:3).
“She conceived, and she bore a son; he²⁵Although the most common text of the midrash says “she”, the actual text of the verse is “he”. called his name Er” – as he was discharged [shehuar] from the world.
“She conceived again, and bore a son; she called his name Onan. She continued and bore a son again, and called his name Shela; and he was in Keziv when she bore him” (Genesis 38:4–5).
“She conceived again…Onan” – as he brought acute mourning [anina] upon himself.
“She conceived again.… Shela” – as he initiated a genealogy [shenishtalshel] in the world.²⁶This translation is based on a variant reading, “in the world [baolam],” instead of “from the world [min haolam].”
“She continued…again…Keziv” – Poskat,²⁷This is the Aramaic name for Keziv. the name of a place.
“Er, Judah’s firstborn, was wicked in the eyes of the Lord, and the Lord put him to death” (Genesis 38:7).
“Er, Judah’s firstborn, was wicked in the eyes of the Lord” – he would plow in the gardens and discharge in the waste.²⁸This is a euphemism for the fact that he would begin intercourse with his wife but then withdraw before discharging the semen so as to avoid impregnating her.