This proverb is deeply embedded in the Chinese consciousness, originating from a famous historical exchange. During the Tang Dynasty, the great Emperor Taizong (唐太宗) asked his famously candid advisor, Wei Zheng (魏徵), what he should learn from the downfall of the previous Sui Dynasty. Wei Zheng replied with this exact phrase, warning the emperor that he must rule benevolently because the people who support him are the very same people who can bring about his ruin. This concept is a practical application of the ancient political idea of the “Mandate of Heaven” (天命 Tiānmìng), which states that a ruler's right to rule is granted by a divine power but is not absolute. If a ruler becomes corrupt and loses the support of the people, they lose the Mandate, and their overthrow is justified.
This isn't just an ancient saying; it's actively used in modern discourse. Its formality lends it weight in serious contexts.