The "निरंजनो निराकार एको देवो महेश्वरः (Niranjano nirakara, eko devo Maheswara)" comes from an ancient Sanskrit tantric text named **Shiva Swarodaya**. This is found in 6th shloka of the text which contains total 395 shlokas:

> देव्युवाच 

> तत्वमेव परं मूलं निश्चितं तत्त्ववादिभिः।

> तत्त्वस्वरूपं किं देव तत्त्वमेव प्रकाशय।।5।।

> Devi said: 

>The tattwas (elements) are the primal cause as ascertained 
by the exponents of the tattwas. O Lord, what is the 
nature of those elements? Kindly reveal that to me. 

> ईश्वर उवाच

> **[निरंजनो निराकार एको देवो महेश्वरः][1]**।

>तस्मादाकाशमुत्पन्नमाकाशाद्वायुसंभवः।।6।।

> Ishwara said: 

>**There is only one birthless and formless supreme 
existence** from which manifests akasha (ether element), 
and from akasha comes vayu (air element) only when he manifests

The text can be found on [Archive][2] with name **Swara Yoga** with commentary and translation by Satyananda Saraswati and on [wikibooks][3] with Hindi translation


  [1]: https://archive.org/details/swara-yoga/page/n135
  [2]: https://archive.org/details/swara-yoga/
  [3]: https://hi.wikibooks.org/wiki/%E0%A4%B6%E0%A4%BF%E0%A4%B5_%E0%A4%B8%E0%A5%8D%E0%A4%B5%E0%A4%B0%E0%A5%8B%E0%A4%A6%E0%A4%AF