When he turned eleven, he began his Islamic studies under his father who was at that time teaching in Jaunpur. He learnt all the books from Mizanus Sarf (Arabic Morphology) till tafsir Baydawi, qualifying at the age of seventeen. After the demise of his father, he studied some books in mathematics under his fathers tutor, Maulana Muhammad Ni’matullah. (1290 A.H)
Allah Ta’ala endowed Maulana Abdul Hayy from childhood with the love of teaching and writing. Any book that he learnt, he taught it thereafter. As a consequence, he developed uncanny ability in every subject. No textbook on any subject remained difficult for him to the extent that he was able to teach books he had not previously studied by any tutor like Al Isharat of Tusi, Al ufuqul Mubin and Qanunut Tibb etc.
He taught for a while in Hyderabad. Subsequently he left for Lucknow where he remained for the rest of his life serving Deen. Maulana Abdul Hayy ibn Fakhruddin Nadwi (1896 – 1923), the father of Maulana Abul Hasan Nadwi and the author of Nuzhatul Khawatir, narrates that he attended Maulana Abdul Hayy’s Majlis (lecture) several times and found him to be extremely intelligent, erudite, an ocean of knowledge, well acquainted with the intricacies Shariah to the extent that he became an internationally recognised scholar. Whenever there was any discussion with scholars, Maulana Abdul Hayy would remain silent until all the scholars had spoken and they would eventually turn to him of a decisive statement. Everyone would unanimously accept his verdict. He was one of the wonders of India and none disputed his matchless virtue.
His students were completely satisfied with his methodology. Maulana Ni’matullah, his teacher, used to extol his praises generously. Due to intense love for writing , he wrote more than a hundred books on many subjects like Arabic grammar, morphology, logic, Jurisprudence and Hadith etc.
He was offered the post of Justice after his father’s demise but refused, considering the dangers of the occupation and being content with the little possessions he had. He felt that had he accepted the offer, it would have impeded his teaching and writing career.
One of the great bounties of Allah Ta’ala upon him was his excellence and compatibility with the science of Hadith and Jurisprudence of Hadith. He always chose a moderate, accepting the view of the Jurists as long as there was adequate proof from Quran and Hadith.
Allah Ta’ala also granted him the ability to see true dreams in which he would be given some indications. He saw Sayyidina Abu Bakr, Umar, ibn Abbas, Fathima. Aisha, Umme Habibah and Muawiyah (radiyallahu anhum ajmaeen). In his dreams and he also met Imam Malik (rah), Shamasud Deen Sakhawi, Imam Suyuti and other scholars, from whom he benefited as mentioned in a separate book on this on this topic.
The Mufti of Makkah, Sheikh Ahmad Ibn Zain Dahlan granted him permission for all isnad (chain of narration) from Al Hidayah of Marghinanai as well as what he had learnt from all his teachers. Mufti Muhammad Ibn Abdullah Hanbali of Makkah, Sheikh Muhammad Ibn Muhammad Al- Gharbi and Sheikh Abdul Ghani Dehlwi also granted him permission for various isnad.
He passed away in Rabi ul Awwal 1304 A.H. at the young age of 39 and was buried in the graveyard of his ancestors.
May Allah Ta`ala enlighten his grave. Ameen.