請觀音經疏闡義鈔 2.77

2.77

經「天尊」者，諸天世人無能過故，故曰天尊，亦曰世尊。古者譯經，二名互用。唐杜行顗譯《佛頂最勝經》，皆稱聖尊。

Regarding the sūtra's "Heavenly Honoured One": because none among heavenly beings or humans can surpass him, he is called Heavenly Honoured One, and also called World-Honoured One. Ancient sūtra translators used the two designations interchangeably. In the Tang dynasty, Du Xingyi's translation of the Foding zuisheng jing uniformly addressed him as Noble Honoured One.