He was the founder of Islamic Educational Trust (IET) together with his wife Aisha Lemu and a friend Ashafa Sani Suleiman.
He had his certificate of General Education for advance level in Arabic, history, Hausa and Persian languages in 1961 and went on to obtain his bachelor's degree Hons in African and Oriental Studies in 1964.
[7][8][9] Lemu started his career in the Bida Native Authority as a teacher of Arabic, Islamic studies and English language.
He taught in the Government Secondary School Bida from 1953 to 1960 and was moved to Kano in 1960, where he became senior teacher of Arabic Language, Islamic Studies and Education.
Lemu's books specialized is the salat, fasting, zakkat and hajj, he clarified and based on IRP Cairo classification, and independent Islamic intellectual.
[24][25] The first task of the establishment was to ensure that all schools both the public and missionary in the North-Western State had qualified teachers for 'Islamic Religious Knowledge'.
The first set of textbooks used in teaching Islamic Religion Knowledge in schools wer written by Lemu, Bashir Sambo and AbdurRahman Doi.
The IET had various programmes, including Annual Seminars for Muslim Undergraduates, Women's Classes, Daawah Mobile Corps and Weekend School.