The song is a plea for occupancy, and it is built on the title that the whole shrine culture of the subcontinent runs on. Khwaja is the honorific of the Chishti masters, and gharib nawaz, the benefactor of the poor, is the name the people of India gave Moinuddin Chishti, and the song opens by calling him both. The request itself is the Sufi heart's oldest prayer: come and dwell inside me, dil mein sama ja.
The second passage makes the case for why he is worth housing. King of kings, and the darling of Ali, ali ka dulaara, which is the genealogy of the Chishti order: it traces itself through Ali, so the saint carries the first family of Islam in his lineage. Then the line that explains the shrine's fame: you have repaired the fate of the destitute, bekason ki taqdeer tune hai sanwaari. Bekas is the one without anyone, and the whole ministry of the shrine is in that word: the people with nobody have him.
The same passage then walks into the shrine itself. The light to be seen there, the saints, the auliya, bowing their heads there. Tu hai hindal wali khwaja: you are the master of Hind, the saint of this land. And the last line of the passage is the most intimate claim in the song: loving you, I have found Mustafa, the Prophet himself. The song climbs the chain of being in three lines, from the saint to the land to the Prophet.
The last passage shifts into the personal and the contractual. Mere peer ka sadka: by the sacrifice of my master, an oath sworn on the saint's own name. I have taken hold of your hem, tera daman hai thama, and the image is the whole theology of the shrine: hold the garment of the saint and be pulled up with him. The storms of my life have moved aside, the intoxication of you has spread over me. Envy of me, however much, is still too little, says the line, because the feet of the saint are the one place the singer refuses to leave.
A.R. Rahman sang it himself, which gives the recording a strangeness no other singer could bring: the composer, in his own voice, at the saint's shrine. The film's scene at Ajmer is one of the most replayed sequences of the decade, and the song is the reason.