Being full of pathos and passion’s heat,
His tete-a-tete thus had the pangs sweet treat.
By flute gets beauty of His Love’s sweet light,
A gift and share good of His Glory and Might.

1.         Tete-a-tete, private conversation between two persons. (here it is wisal-i-llahi; t. of God).
Treat; something that comes unexpected, especially something that gives pleasure, not often enjoyed.

Here Iqbal’s wants self on tete-a-tete differs from other mystics. It is neither pantheism nor neo-platonism as enunciated by Plotinus (Plotinus) 205-270 A.D. in Alexandira postulating a single source (God) from which all forms of existence emanate and with whom the soul seeks mystical union. It is also called ‘Hama andar Wajud” (all within His Being) or “wahdat-is-shahud”. His self goes higher to both, higher than “fana-fihlah” (destruction or elimination within God).

Here poet’s self wants to achieve ‘Baqa Billah” (permanence! everlasting life with God. This is the highest stage for a faithful when the self feels his entity alongwith the God’s (presence) vision. As such in his tete-a-tete of God the self is still conscious of long period of separation from that place, the place of souls in the heavens (Alami Arwah).
Iqbal is hinting here to those sweet pangs of separation
(a) Wisal-i-ou; (his tete-a-tete) (b) Zubandan-i- (having the tongue, the ken of the feeling of), Judai, (separation). Flute; (his songs of lover message of love, poesy of amatory, his poesy full of love of God.
Use tete-a-tete talk (Taht-e-tete) as we say he dined tete-a-tete with the Prime Minister.
From Griftan (inf.) gired is the (aorist tense )