Yahweh asks this question because he has lost patience with the people. It can be translated as a statement. Alternate translation: "I have tolerated this evil community who has criticized me long enough." (See: [[rc://en/ta/man/translate/figs-rquestion]])
The word "complaining," an abstract noun, can be expressed as a verb. Alternate translation: "I have heard the people of Israel complain" (See: [[rc://en/ta/man/translate/figs-abstractnouns]])