The pronoun refers to the Commander of the Faithful, up to his saying—Exalted is His might: “And he is the Lord of the Earth.” (And in it is a distinction: then our Master—Exalted is His might—declared that the Wali [Guardian/Saint] is encompassing of all things.)
❖ From Surah Ash-Shura ❖
The First Verse: [“Ha-Mim. ‘Ayn-Sin-Qaf.”] 1
[125] It came in Mashariq al-Anwar—meaning the Lights of Certainty—that al-Sadiq—Exalted is His might—said: “‘Ayn-Sin-Qaf contains the secret of Ali; thus, his Greatest Name was made a symbol in the opening [letters] of the Quran.” This is the allusion to [the saying]: “There is no prayer except with the Opening of the Book (Fatihat al-Kitab),” and its meaning is that there is no prayer for the servant, and no connection (sila) with the Lord, except through the guardianship (wilayah) of Ali and the knowledge of him.