English: Identified handwriting of Guru Nanak from the Guru Harsahai Pothi. This is an early rendition of the Mul Mantar - the basic, root, credal statement of Sikhism. It is believed Guru Nanak gave his writings to Guru Angad after he passed on the guruship. During this time the Gurmukhi script was still in its developing stages. As such, there was no "Kanna" in the Gurmukhi writing here. The script used by Guru Nanak here is most likely an early stage of what would become Gurmukhi, referred to as 'proto-Gurmukhi' by scholars and academics. The writings of Guru Nanak and other early gurus were kept by their custodians, the Sodhis of Guru Har Sahai, who claim to be the descendants of Guru Ram Das through his second son, Meharban. Unfortunately, it is believed the Guru Har Sahai Pothi is now lost.

Note: the word 'pothi' originally meant 'book' in Punjabi. However, amongst Sikhs the term evolved to refer to a sacred book, especially one containing gurbani or scriptural texts and of a moderate size (smaller excerpts are referred to as 'gutkas').

This particular folio was published with a caption in Punjabi that read: "ਪੰਥੀਆਂ ਗੁਰੂ ਹਰਿਸਹਾਇ ਵਾਲੀਆਂ ਵਿਚੋਂ ਇਕ ਭਾਗ ਦਾ ਆਰੰਭਕ ਸਫ਼ਾ ੴ ਸਤਿਨਾਮ-ਬਾਬਾ ਨਾਨਕ"(rough translation: 'The opening page of one of the Guru Harsahai Vali Pothi ੴ Satnam Baba Nanak')

URL: https://www.flickr.com/photos/akaalsingh/3370607333/

Further reading: https://doi.org/10.1093/0195130243.003.0003

"Two facsimiles of Guru Har Saha Pothi that appear in Giani Gurdit Singh's Ithas Sri Guru Granth Sahib. The first facsimile presents the so called earliest form of the Mul-Mantra [Mul Mantar] whereas the second carries the text of a pada of Kabir in Sri raga." (description taken from: link