The great poet and philosopher, Allama Iqbal, who conceptualized and elaborated upon the concept of Khudi (the philosophy of Selfhood), considered the 19th century poet, Daagh Dehlvi to be his master.

As has been encapsulated by Zafar Anjum in the book Iqbal: The Life of a Poet, Philosopher and Politician –
“His (Iqbal’s) earliest poems are published in Delhi’s Zabaan magazine in the issue of November 1894. The last couplet of one of his published ghazals in Zabaan is:

Garam hum par jo kabhi hota hai who bu’t Iqbal
Hazrat-e-Daagh ke ashaar suna dete hain

Whenever that idol gets cross with me, Iqbal
I recite to her the couplets of respected Daagh

Emboldened by his early success, Iqbal decided to approach Daagh Dehalvi, ustaad to the nizam of Deccan, and the most famous Urdu poet of his era, for mentoring. Though they are thousands of kilometres apart from each other, the relationship of master and disciple is established through correspondence. Iqbal sends Daagh some of his ghazals for correction. Daagh accepts him as his student and sends back Iqbal’s poems with comments and advice.
There is nothing extraordinary in this mentor-mentee relationship: Daagh is so popular as a poet throughout India that hundreded of emerging poets send him their compositions for advice by Dak. The demand for Daagh’s mentorship is so high that he has to establish a separate department with dedicated staff to look after the flood of poetic correspondence.
After a brief correspondence, Daagh concludes that this young poet from Punjab (Iqbal) is extraordinarily talented. He writes to him that there is not much he can do to improve Iqbal’s compositions. Consequently, the correspondence does not last very long. Regardless, Daagh will remember Iqbal throughout his life and so will Iqbal.

Though the two will never meet in person, Iqbal will continue to address Daagh as his mentor. Iqbal expresses his strong desire to meet Daagh in the following manner:

Yehi hai jo shauq-e-mulaqat-e-hazrat
Toh dekhenge ek bar mulk-e-dakan bhi

If this is the intensity of desire to meet His Highness
I will surely visit the Deccan at least once

In a ghazal published in 1896, Iqbal pays tribute to Daagh in the following words:

Zaseem o Tishna hi Iqbal kuchh nazaan nahin un par
Mujhe fakhr hai shagirdi-e-Daagh-e sukhandaan ka

It’s not that only Naseem and Tishna are proud of him, Iqbal
I too am proud of being a disciple of Daagh, the master of verses

And in yet another ghazal of the same period, he has this to say about his master:

Janaab-e Daagh ki Iqbal yeh saari karamat hai
Tere jaise to kar dala, sukhandaan bhi sukhanwar bhi

You owe it to the miracle of Daagh, O Iqbal
That a worthless poet like you has become a master versifier