He went forth on the second day, and saw two Hebrew men striving. Who were they? || Dathan and Abiram, as it is said, "And he said to him that did the wrong, Wherefore smitest thou thy fellow?" (Ex. 2:18). Dathan said to him: What! Dost thou wish to kill me with the sword of thy mouth as thou didst kill the Egyptian yesterday, as it is said, "Who made thee a prince and a judge over us? Speakest thou to kill me, as thou killedst the Egyptian?" (Ex. 2:14). "Seekest thou to kill me" is not written (in the Scripture) here, but "Speakest thou to kill me."
Why Moses Fled Egypt and Escaped to Midian
Pirkei DeRabbi Eliezer 48:10