מדרש אויף בראשית 24:8

“Abraham said to him: Beware lest you return my son there” (Genesis 24:6).
“The Lord, God of the heavens, who took me from my father's house, and from my birthplace, and who spoke to me, and who took an oath to me, saying: To your descendants I will give this land; He will send His angel before you, and you will take a wife for my son from there” (Genesis 24:7).
“Abraham said to him: Beware…the Lord, God of the heavens, who took me from my father’s house” – this refers to his father’s house. “And from my birthplace” – this refers to his neighborhood. “And who took an oath to me” – in Ḥaran. “And who spoke to me” – [at the covenant] between the pieces.³²See Genesis 15:1–21. “He will send his angel before you” – Rabbi Dosa said: This refers to a particular angel.³³Some say this refers to the archangel Metatron. At the moment that Abraham our patriarch said: “He will send his angel before you,” the Holy One blessed be He designated two angels for him; one to bring out Rebecca, and one to accompany Eliezer.
“And if the woman will not wish to follow you, you shall be absolved from this oath of mine; only you shall not return my son there” (Genesis 24:8).
“And if the woman will not wish…only [rak] you shall not return my son there” – rak is a term of exclusion, [intimating:] My son will not return there, but my grandson [Jacob] will return.