My thanks to my friend Christopher Davis for providing the following:
“Now Abram dwelt near the oak
called Ogyges: the place belongs to Canaan, not far from the city of Hebron.
But being uneasy at his wife’s barrenness, he intreated God to grant that he
might have male issue: and God required of him to be of good courage, and said,
that he would add to all the rest of the benefits that he had bestowed upon
him, ever since he led him out of Mesopotamia, the gift of children.
Accordingly Sarai, at God’s command, brought to his bed one of her
hand-maidens, a woman of Egyptian descent, in order to obtain children by her:
and when this handmaid was with child, she triumphed, and ventured to affront
Sarai; as if the dominion were to come to a son to be born of her. But when
Abram resigned her into the hands of Sarai, to punish her, she contrived to fly
away; as not able to bear the instances of Sarai’s severity to her; and she
intreated God to have compassion on her." - Josephus, Antiquities of the
Jews, Book 1, X:IV
Next, in the Midrash Genesis
Rababah, we read:
"R. Simeon b. Yohai said:
Hagar was Pharaoh's daughter. When Pharaoh saw what was done on Sarah's behalf
in his own house, he took his daughter and gave her to Sarah, saying, Better
let my daughter be a handmaid in this house than a mistress in another house '
; thus it is written, And she had a handmaid, an Egyptian, whose name was
Hagar, he (Pharaoh) saying, 'Here is thy reward (agar),' Abimelech, too, when
he saw the miracles performed in his house on Sarah's behalf, gave his daughter
to her, saying, 'Better let my daughter be a handmaid in this house than a
mistress in another/ as it is written, Kings' daughters are among thy
favourites (Ps. xlv, 10): viz. the daughters of [two] kings. At thy right hand
doth stand the queen in gold of Ophir (ib.) — this alludes to Sarai.
And Sarai said unto Abram: Behold
now, the Lord hath restrained me from bearing, etc. (xvi, 2). Said she : I know
the source of my affliction : it is not as people say [of a barren woman], 'she
needs a talisman, she needs a charm,' but Behold now, the Lord hath restrained
me from bearing.
It may be that I shall be builded
up through her. It was taught : He who has no child is as though he were dead
and demolished. As though dead : And she said unto Jacob: Give me children, or
else I am dead (Gen. xxx, 1). 5 As though demolished: It may be that I shall be
builded up through her, and only that which is demolished must be builded up.
And Abram hearkened to the voice of Sarai.
R. Jose said : To the voice of the
Holy Spirit, (which he felt moved her to speak) as you read, Now therefore
hearken unto the voice of the words of the Lord (1 Sam. xv, 1)." - Genesis
Rabbah: 45:1-2
Additionally the Midrash Tehilim
records the taking of Hagar as a wife one of the ten trials by which Abraham
was "purified".
אמרת ה’ צרופה. שצרפו הקב”ה בעשר נסיונות.
ואלו הן – כשירד לתוך כבשן האש, שנאמר (שם טו, ז) אני ה’ אשר הוצאתיך מאור כשדים. שנים,
כשאמר לו לך לך. ושנים בשרה. בהגר, (שם טז, ב) בא נא אל שפחתי. ובישמעאל, (שם כא, י)
גרש האמה הזאת. ובמלכים, (שם יד, יד) וירק את חניכיו.
ובמילה, שאמר לו הקב”ה (שם יז, א) התהלך
לפני והיה תמים. ובין הבתרים, כשראה המלכיות משעבדות לבניו. וביצחק, (שם כב, ב) קח
נא את בנך את יחידך.
(Translation)
"God’s saying is pure” – he
[Avraham] was purified by ten trials. And these are [the ten trials]: 1. He was
thrown into the furnace, as it says, “I am God that took you out from Ur
Kasdim.” 2. God instructed him, “Go for yourself.” 3 & 4. Two tests
concerning Sarah. 5. Hagar, as it says, “Consort, now, with my maid-servant.”
6. And with Yishmael, as it says, “Drive out this slave-woman [with her son].”
7. [Going to war] with the kings, as it says, “He armed his disciples.” 8.
Circumcision: that God instructed him, “Walk before Me and be perfect.” 9. In
the Covenant Between the Parts, when he prophesied that his descendants would
be enslaved in four exiles. 10. With Yitzchak (Isaac): “Take, please, your son,
your only one."
“And the LORD was aware that
Abraham was faithful in all of his afflictions because he tested him with his
land, and with famine. And He tested him with the wealth of kings. And He
tested him again with his wife, when she was taken [from him], and with circumcision.
And He tested him with Ishmael and with Hagar, his maidservant, when he sent
them away. And in everything in which He tested him, he was found faithful. And
his soul was not impatient. And he was not slow to act because he was faithful
and a lover of the LORD.” - Jubilees, Book of Division, 17:17-18