The Chinese Idiom ‘to leave one (or three) side of the net open or give the wrongdoer a way out’ are derived from the story of Emperor Tang of Shang Dynasty.
One day Tang went out and saw a rustic, who was spreading nets in every direction, and vowing that every bird in the sky should go into his net.
Tang said, ‘What! all?’
Then, taking away the nets on three sides, he vowed that those which wanted to go to the left should go left, and those which wanted to go right should go right, and that only those which were the victims of fate should be caught in the net.
The princes, hearing of it, said, ‘Tang’s kindness is extreame, and extends even to birds and beasts.’
At this time Jie of Xia was oppressive, and his rule dissipated, and one of the princes Kunwu rebelled, so Tang, levying an army, put himself at the head of the princes. They marched against Kunwu, and then attacked Jie of Xia. They overthrew the Xia Dynasty and established the Shang Dynasty