Numbers 11:10

Then Moses heard the people weep throughout their families, every man in the door of his tent, for the contagion of dissatisfaction had spread throughout the camp like a virulent pestilence; and the anger of the Lord was kindled greatly; Moses also was displeased. With this second outbreak of dissatisfaction, Moses felt the whole wrath of God in his inmost soul, and he feared that his entire mission was a failure.