What are the Sufi allusions in the attached poem, and do they exist in it at all? If they do exist, what are their instances? And what is the understanding of these allusions?

Al-Hallaj is one of the most prominent proponents of the false doctrine of hulul (incarnation/indwelling) and ittihad (union with God). When Sheikh Al-Islam Ibn Taymiyyah was asked about the ruling on one who holds Al-Hallaj's belief, he replied that whoever believes what Al-Hallaj believed, from the statements for which he was executed, is a disbeliever, an apostate, by the consensus of Muslims; this is due to his saying of hulul and ittihad and other such statements of the people of zandaqa (heresy/apostasy) and ilhad (atheism/deviation), such as his saying: "I am God." Al-Hallaj also had tricks and various types of magic. The opening of the mentioned poem by Al-Hallaj alludes to this belief, where he says: "So I said: Who are you? He said: You are I," and likewise, the rest of the poem is overflowing with this corrupt meaning. Fana' (annihilation) among the Sufis is the annihilation of the servant's essence into the Lord's essence, so human attributes vanish, and divine attributes remain, and the servant and the Lord become one. This state of fana' is what many Sufi sheikhs claimed as hulul and ittihad.