Midrash Tanchuma Buber, Emor 16

[ד"א שור או כשב]. שור בזכות אברהם, שנאמר ואל הבקר רץ אברהם (בראשית יח ז), כשב בזכות יצחק, שנאמר והנה איל (שם כב יג), עז בזכות יעקב. שנאמר לך נא אל הצאן וקח לי משם שני גדיי עזים טובים (שם כז ט), מהו טובים, אמר ר' ברכיה בשם ר' חלבו טובים לך וטובים לבניך, טובים לך שעליהם אתה מתברך, וטובים לבניך שעליהם מתכפר להם. [Another interpretation of (Lev. 22:27): A BULL OR A SHEEP < OR A GOAT >. The BULL was due to the merit of Abraham, of whom it is stated (in Gen. 18:7): THEN ABRAHAM RAN UNTO THE HERD (for a calf to feed his heavenly visitors).⁶⁸Tanh., Lev. 8:12; Lev. R. 17:9; PRK 9:9. The SHEEP was due to the merit of Isaac, of whom it is stated (in Gen. 22:13): AND THERE WAS A RAM (to replace an obedient Isaac as a sacrifice). The GOAT was due to the merit of Jacob, of whom it is stated (in Gen. 27:9): PLEASE GO UNTO THE FLOCK, AND BRING ME TWO GOOD KIDS OF THE GOATS FROM THERE. What is the meaning of GOOD (in reference to the two kids)? R. Berekhyah said in the name of R. Helbo: < They are > good for you and good for your children.⁶⁹Gen. R. 65:14; PR 47:4. < They are > good for you, because through them you are blessed;⁷⁰When Jacob brought the meat from the goats to his father, he received a blessing. and they are good for your children because through them atonement is granted you (on the Day of Atonement).