At the time of the Ninkaku's death, FUJIWARA no Munetada said that 'he knew well about the mantra and especially efficacious methods in esoteric Buddhism. It is a real pity that he passed away suddenly. Not only the Emperor (Emperor Horikawa) but also all his family are mourning.' (in the section of March 28 in 'Chuyu-ki dairy').
藤原宗忠は仁覚の死に際し、「于今伝真言道、殊有身験、而忽被赴他界、誠是哀哉、従主上（＊堀河天皇）始、一家人々又嘆也」（「中右記」3月28日条より）と書き残している。