Jun Wu Xie had asked to leave Jun Gu's body in her courtyard. As she was unable to touch the Soul Jade, Jun Wu Xie could only inspect Jun Gu's physical body.
Her findings were beyond her expectations. Jun Gu's body seemed as though it had been frozen when he died, and all his organs were still completely intact, with no signs of organ failure.
Ten years, not ten days, it could only be due to the Soul Jade. Jun Wu Xie could not think of any other reason that Jun Gu's body could be so well preserved.
She knew from having touched the Soul Jade that it would exert an immense force to draw in unstable souls. When Jun Gu died, his body had been sent back to the Lin Palace immediately and was laid to rest the very next morning. That half of the Soul Jade had been placed in his mouth then and had stayed there ever since.
Jun Wu Xie had good reason to believe, that Jun Gu's soul had not completely dispersed, and could very well be trapped within the Soul Jade.