Musar zu Divrej Hajamim II 6:42

Abraham bound his son, and the Holy One, Blessed is He, swore to remember this merit to the credit of his children for generations and generations. When Israel sinned with the golden calf, Moses, upon him is peace, stood in prayer and said: "Remember the deeds of Abraham, Isaac and Israel thy servants" (Exod. 32:31), and so Solomon prayed : "Remember the good deeds of David Thy Servant" (II Chron. 6:42), and their prayers were answered. And thus we mention every day the merits of the fathers (in our daily prayers).