Bu Hong's master was Lu Tie, the Sanctum Leader of Azure Dragon Sanctum. He was also one of the strongest Golden Flame Elders in the Fire Worship Sect. A person like him would, naturally, own a Thousand Inscriptions Saint Weapon.
For this reason, Bu Hong had a better understanding of Thousand Inscriptions Saint Weapons compared to others. 'If the sword he used is merely a Thousand Inscriptions Saint Sword, even with his assist-type Divine Ability and if he used all his martial tactics and Divine Abilities that he has mastered to their highest degrees, it would still be impossible for his attack to be so fast! I've already opened my Spiritual Eyes when I broke through to the Third Form of the Saint Celestial Stage that's also known as the Spiritual Eyes Form. Even then, I barely managed to catch a glimpse of his attack! What does this mean? Doesn't this mean his sword is of a higher grade than a Thousand Saint Inscriptions Weapon?'