The relic left behind by Buddha was considered as a rare treasure in the world. To cultivators, it meant something more. This was so as Buddha had walked to the end of cultivation.
There were thousands of different ways to cultivate, and yet at the pinnacle, they all converged to the same point.
The Daoist and Buddhist Scriptures were lengthy, but they were all unveiling the ultimate truth in life and in the universe. Just as what Lu Jiuyuan said, "Thousands of scriptures were instilled into me, and I instilled myself into thousands of scriptures". He was not being arrogant, but when one had reached the top, it was as though one had been placed at the peak of a tall mountain. At that spot, one would see all of the sky, ground, mountain, and river, one would be able to see the future and the past, and one would ponder about them.