Which sentence of the old adage "A friend in need" is clearly reflected?

The strength of a horse is known from a distance, but a friend in need is a friend indeed. This old adage is vividly reflected in this story. Zhao Dongmen was an official and crowded; After being removed from office, there were few horses and chariots in front of the door; When it is used again, there is an endless stream of cars and horses in front of the door. This is really like a farce, in which the world is cold. The whole world is different. Wu is a man who doesn't change his attitude with the gain and loss of wealth. His promotion to Zhao Dongmen is consistent. Especially after the death of Zhao Dongmen and his son, he took Zhao's little grandson as his own son. This quality of Wu is really admirable.