It is said that his name appeared for the first time in an article related to the mobilization carried out in 994 in order to pursue and apprehend the robbers, and this article informed that he was called up together with TAIRA no Koremasa (TAIRA no Sadamori's son) and his nephews, MINAMOTO no Yorichika and MINAMOTO no Yorinobu, and others, in search for the robbers ("Nihongi Ryakuki" (Summary of Japanese Chronologies) and the article of the 6th day of the 3rd month of the 5th year of Shoryaku (old lunar calendar) or the article of April 24, 994) in "Honcho seiki" (Chronicle of Imperial Reigns)).
正暦5年（994年）に行われた盗賊の追捕に際して、平維将（平貞盛の子）や甥の源頼親、源頼信らと共に武者として捜索に動員されたことを伝える記事が初見とされている（『日本紀略』、『本朝世紀』同年3月6日(旧暦)条）。