Pesukei d’Zimrah: Divrei Binah: From My Ancestors
“This is my Lord and I will beautify Him; the Lord of my father and I will exalt Him (Exodus 15:2).” Rashi comments on, “the Lord of my father,” I am not the beginning of this holiness, but simply holding on to the holiness and the awareness of God’s Lordship that derives from my ancestors.
The reason this is necessary is that if we were to claim that our holiness and awareness of God is our own, we would be vulnerable to the attacks and prosecution of Satan. However, when we acknowledge that what ever we have achieved is rooted in what our ancestors accomplished and planted inside of us, then the holiness and awareness are invulnerable to attack and prosecution. (Chelkat Yehoshua, Bishalach)