Mawlana 'Ubaydullah Sindhi on Mawlana Gangohi.

Al Salamu 'Alaykum.

Mawlana ‘Ubayd Allah Sindhi (may Allah shower His mercy upon him) writes: 

‘‘Shaykh al-Islam Abu Mas‘ud Rashid Ahmad Gangohi is the son of Hidayat Allah Ansari. He was born in 1244 AH, and learnt from Mawlana Mamluk ‘Ali [Nanautwi], Mawlana ‘Abd al-Ghani [Dehlawi], Mawlana Ahmad Sa‘id [Dehlawi], and Mawlana Imdad Allah [Muhajir Makki] etc. I personally studied a large portion of Sunan Abi Dawud from him. Allah granted me immense benefit through it. It is the effect of Mawlana Rashid Ahmad’s company that I followed his maslak in such a way that I never even contemplated moving away from it. Through him, the Wali Allahi approach to fiqh and hadith became manifest to me, and through his blessings I became well versed in the fundamentals as well as advanced rational discourse in the sciences of fiqh,suluk & ma‘rifah, Arabic and the Qur’an & Sunnah. I found Mawlana Rashid Ahmad to be a well-versed imam and mujtahid of the Hanafi School. He conformed strictly to the school of thought of his teacher, Mawlana ‘Abd al-Ghani, and was as unshakeable as a mountain in this regard. He closely resembled Mawlana Muhammad Ishaq [Dehlawi][1] in the Wali Allahi maslak. I understood the reality of sunnah and bid’ah from his book, Barahin-e-Qati‘ah. He had authored this book in support of Shah Isma‘il Shahid’s work, Idah al-Haq. Mawlana Rashid Ahmad became the Imam of the Deobandi group after Amir Imdad Allah and Mawlana Qasim [Nanautwi][2]. In excess of three thousand shaykhs attained religious knowledge from him. His year of passing is 1323 AH.’’ 

Shah Wali Allah awr unki Siyasi Tehrik, p. 197 (Sindh Sagar Academy, 2008 ed. by Mawlana ‘Ubayd Allah Sindhi)
http://zakariyya.wordpress.com/2009/10/05/mawlana-rashid-ahmad-gangohi-and-the-wali-allahi-tradition/
Wa'laykum Salam.