From his exodus from Mt. Hiei (1175) through the lectures at Todaiji (1190) and the Gyakushu seppo sermons (1194), Honen's religious experience deepened, until in his later years, he experienced nembutsu samadhi (nembutsu zammai). Nembutsu samadhi is traditionally attained through concentrating one's mind on a visualized image of Amida Buddha and the Pure Land. In Honen's case, he focused on exclusive recitation of the nembutsu which led to an experience of seeing Amida Buddha and the Pure Land.
Honen wrote about this experience in the Sanmai-hottokuki which is found in a number of different versions (SHZ. 863-65). One is contained in the Daigobon Honen Shonin Denki, an older version of Honen's biography compiled about 30 years after Honen's death by his disciple Genchi. The other is contained in the biographical Genku Shonin Shinniki of roughly the same period. This text also is found as part of a larger transcription of Honen's sermons transcribed in Shinran's Saiho Shinnansho. Finally, there is a version found in Ryukan's Chionkoshiki. Additionally, Honen speaks of this experience in Chapter 16 of the Senchakushu which was thought to be written in 1198 when he was sixty-six.(for more on the biographies)
According to the Sanmai-hottokuki, Honen experienced this samadhi and saw the Pure Land several times between 1198-1206. In the main body of the Sanmai-hottokuki, Honen himself speaks of his visualizing of the sun, water, ground and various physical aspects of the Pure Land as taught in the Meditation Sutra (Kuan wu-liang-shou ching). Traditional biographies support the idea that Honen's composition of the Senchakushu emerged from this personal religious experience. Since this period roughly corresponds to time when the Senchakushu is thought to have been written, it is entirely possible that such experiences influenced its composition (Takahashi, 187-207). In the last chapter of the Senchakushu, Honen states that the reason he relied on Shan-tao was because he was the teacher who attained nembutsu samadhi. Honen's subsequent assertion that Shan-tao was a manifestation of Amida Buddha is perhaps also understood in light of these visualization experiences. This final religious experience of Honen's life is, therefore, seen as the foundation for his seminal work, the Senchakushu, and also as the final fruit of his religious conversion at age forty-three in 1175.
Takahashi Koji, "Senchakushu no seikaku ni tsuite: tokuni hi ronriteki ichimen o chushin to shite." in Jodokyo no shiso to bunka, Etani Festschrift (Kyoto: Dohosha, 1972).
Through reciting the nembutsu, the Pure Land and Seishi bosatsu appear (nembutsu-ni yori gokuraku-ya seishi bosatsu-o genzuru) from the Honen Shonin gyojoezu, Scroll 7, section 23-24.