Midras Mazmur 27:2: Mekhilta DeRabbi Yishmael & Vayikra Rabbah

And (this obtains) not with Egypt alone, but with all who afflict Israel throughout the generations. As it is written (Psalms 78:66) "And He beat back His foes. Eternal disgrace did He inflict upon them, viz. (Psalms 81:15-16) "In a moment I would humble their foes … and their time (of punishment) will be eternal", and (Isaiah 14:25) "to break Ashur in My land, etc." And thus, throughout the generations, viz. (Ibid. 26) "this is the counsel for all of the earth, and this is the hand stretched forth against all the nations" (that afflict Israel). Why so? (Ibid. 27) "For the L–rd of hosts has counseled, and who will annul it? And His hand is stretched forth, and who will turn it back?" Not Egypt ("Mitzrayim") alone, then, (is intended), but all who afflict ("meitzarim") them, throughout the generations. Thus — "for the L–rd wars for them against Mitzrayim (- "meitzarim").

“With this Aaron shall come into the Sanctuary: with a young bull as a sin offering, and a ram as a burnt offering” (Leviticus 16:3).
“With this Aaron shall come” – that is what is written: “Of David. The Lord is my light and my salvation; whom shall I fear? [The Lord is the stronghold of my life; of whom shall I be afraid?]” (Psalms 27:1). Rabbi Elazar interpreted the verse regarding the sea. “My light” – at the sea, as it is stated: “It illuminated the night” (Exodus 14:20). “And my salvation” – “stand and see the salvation of the Lord” (Exodus 14:13). “Whom shall I fear?” – “Moses said to the people: Fear not” (Exodus 14:13). “The Lord is the stronghold [maoz] of my life” – “the Lord is my strength [ozi] and my song” (Exodus 15:2). “Of whom shall I be afraid?” – “may terror and fear descend upon them” (Exodus 15:16). “When evildoers approach me” (Psalms 27:2) – “Pharaoh approached” (Exodus 14:10). “To consume my flesh” (Psalms 27:2) – “the enemy said: I will pursue, [I will overtake…my desire shall be satisfied through them]” (Exodus 15:9). Rabbi Shmuel bar Naḥman said: The wicked one does not depart from the world until he utters his punishment from his mouth. “The enemy said: I will pursue...” – it does not say: “My hand will dispossess them [torishem]” but rather, “torishemo” (Exodus 15:9); I will bequeath [morish] my wealth and glory to them. “My foes and my adversaries are mine [it is they who stumble and fall]” (Psalms 27:2) – “He tossed Pharaoh and his army [in the Red Sea]” (Psalms 136:15). From here on, Israel said: “If a camp” (Psalms 27:3) of Egyptians “besieges me, my heart will not fear” (Psalms 27:3). If war” (Psalms 27:3) with Egypt “comes upon me, in this I will put my trust” (Psalms 27:3); in that which You promised me, as it is stated: “The Lord will wage war on your behalf” (Exodus 14:14).

Rabbi Shmuel bar Naḥman interpreted the verse regarding the Philistines. “When evildoers approach me,” this is Goliath, as it is stated: “The Philistine approached every morning and evening” (I Samuel 17:16). “To consume my flesh” – “The Philistine said to David: Come to me and I will give your flesh to the birds of the heavens” (I Samuel 17:44). Rabbi Abba bar Kahana said: The land took hold of him.¹Goliath was unable to move quickly, as though he was held down by the ground itself. This was so that he would not reach David before David could employ his slingshot against Goliath (Etz Yosef). Rabbi Tanḥuma said: I will state a source; it does not say: “I will come to you,” but rather “come to me.” This teaches that the land took hold of him. Rabbi Yanai says in the name of Rabbi Shimon ben Rabbi Yanai: The Holy One blessed be He placed two hundred and forty-eight iron fetters on the two hundred and forty-eight limbs that are in a person.
At that moment David said: “Lord, do not grant the wishes of the wicked” (Psalms 140:9); do not grant his desires. “Do not untie his muzzle” (Psalms 140:9); do not loosen it for him.²This phrase is often translated “do not bring to fruition his scheme [zemamo].” However, the word zamam can also mean muzzle, and therefore the midrash translates the verse to mean do not untie, or loosen, his muzzle [zemamo]. “May they elevate, Selah” (Psalms 140:9); restrain his shoulders. Rabbi Yudan said: He lusted after David, who was: “With beautiful eyes and a lovely appearance” (I Samuel 16:12). Immediately, David said: “Lord, do not grant the wishes of the wicked” (Psalms 140:9); do not grant his desires, but rather, “grant the desire of the righteous” (Proverbs 10:24).
The Rabbis say: [God] afflicted [Goliath] with leprosy, as it is stated: “The Lord will deliver you [yesagerkha] into my hand” (I Samuel 17:46), and this [term], yesagerkha, is nothing other than leprosy, just as it says: “The priest shall quarantine him [vehisgiro]” (Leviticus 13:4). “My foes and my adversaries are mine” – “the stone penetrated his forehead” (I Samuel 17:49). From there on, David said before the Holy One blessed be He: “If a camp” – of Philistines – “besieges me, my heart will not fear.” “If war” – with the Philistines – “comes upon me, in this I will put my trust” (Psalms 27:3), “In this [bezot]” – Rabbi Levi said: In the testament that Moses dictated to us in the Torah when he said to the elders: “This is [vezot] for Judah” (Deuteronomy 33:7).³The verse concludes: “You will be help against his adversaries.”