Shenron Was Not Omnipotent

"This box is really sturdy!" Yamcha stopped attacking and stared seriously at the box. Neither Goku's Kamehameha nor his own Wolf Fang Fist had been able to damage it. The material used to make this box was truly extraordinary. "Bring it to me." Seeing their helplessness before the box, He-El held out his hand for them to let him take a look. "Here, Big Brother He-El. We can't open it." Goku picked up the box and handed it to He-El.