I hate the congregation of evildoers. Which congregation is this? The congregation of Korah, as it is said (Numbers 16:19), "And Korah assembled all the congregation against them." And which congregation do I love? (Exodus 35:1) "And Moses assembled all the congregation of the children of Israel." (1 Kings 8:1) "Then Solomon assembled the elders of Israel." And I will not sit with the wicked. This is the congregation of Korah, as it is said (Numbers 16:26), "Depart now from the tents of these wicked men."
Kingdom of Korah
Midrash Tehillim 26:4