MIDRASH TEHILLIM
1.....(9.6)
When mine enemies are turned back...
According to Rabbi Phinehas, these words mean - When my enemies are made to turn back, by the means described in the verse: "And a messenger came to Saul, saying, "Make haste and turn back, for the Philistines have spread out over the land!"" (Shmuel I - I Samuel 23:27), that is, the messanger came from above, his coming being refered by David in the verse: "He sent from on high [and] He took me;" (Shmuel II - II Samuel 22:17)
2.....(9.6)
...they stumble and perish at Your presence;
Means that Israel said to God: "Master of the Universe! Even if my enemies have no sin other than that of going into Your house and speaking brazenly in Your presence, they will fall and perish."