Musar su Salmi 110:1

Although all the patriarchs have been described as the מרכבה, they are all included when Abraham is mentioned; he, being the "father" of them all, represents them also. This is the reason that the first benediction in the daily עמידה prayer concludes with the signature מגן אברהם, "shield of Abraham." The term "shield" is used to describe those who support the מרכבה, namely חסד, גבורה, תפארת. This too is the deeper meaning of the words (15, 1) אנכי מגן לך שכרך הרבה מאד, "I am your shield, your reward is very great." Malki Tzedek, king of Shalem, alludes to something similar in Bereshit (14, 19-20): ויברכהו, ויאמר: ברוך אברם לא-ל עליון קונה שמים וארץ וברוך א-ל עליון אשר מגן צריך בידך. "He blessed him saying: Blessed be Abraham of G–d Most High, Owner of Heaven and Earth. And blessed be G–d Most High, who has delivered your foes into your hand." The Zohar on that verse understands this as a reference to the daily עמידה prayer when we say very similar sounding words in the first benediction. If one examines the composition of that benediction closely one can view the words אלוקי אברהם, אלוקי יצחק, אלוקי יעקב as corresponding to the words ברוך אברהם. The words א-ל עליון גומל חסדים טובים correspond to the words וברוך א-ל עליון. The words קונה הכל corresponds to Malki Tzedek's words קונה שמים וארץ. We find similar wording in the repetition of the Friday night עמידה. Finally, the signature of that first benediction of the daily עמידה is מגן אברהם, corresponding to the last words in Malki Tzedek's blessing אשר מגן צריך בידך. It is true that we also encounter the formula in מגן דוד, "shield of David." The difference is that whereas מגן אברהם includes the other carriers of the מרכבה as we have explained, David is the recipient of the foregoing including the parts of the מרכבה that Abraham comprises, seeing that he, David, personifies מלכות. As such David provides the "fourth leg" of that four- cornered מרכבה that we have described as the מרכבה ארג"מן. At any rate, the significance of the promise to Abraham in 12,2 והיה ברכה, "be a blessing," is that בך חותמים, "they will conclude the benediction using your name," is clear. We shall come back later to the meaning of מגן דוד.

Abraham hinted to Lot later that there is an ארץ ישראל העליונה, a spiritual equivalent to the terrestrial land of Israel, as we know from Sanhedrin 90 based on Isaiah 60,21: "Your people are all righteous, they will inherit an eternal land." Abraham hinted to Lot that both he and Lot would qualify for that future and that they would both reside in Heaven close to G–d. Yalkut Shimoni on Psalms 110,1: The Lord said to my lord "sit on my right side while I make your enemies your footstool," quotes Rabbi Yudon saying that in the future G–d will seat the Messiah on His Right and Abraham on His Left, and that Abraham will feel aggrieved at being assigned the left saying "how can my grandson be assigned the right side while I have to be content with the left side?" G–d will placate him saying: "Your grandson sits on My right, whereas I sit on your right side, וענותך תרבני, "and Your providence has made me great" (based on Samuel II 22,36). Thus far the Yalkut.