This is a commentary on "Treatise on the Pure Land" (its formal name: "Muryoju-kyo Ubadaisha Ganshoge" [Upadesa on the Sutra of Immeasurable Life]) written by Tenjin (Seshin) (Vasubandhu).
天親（世親）撰述の『無量寿経優婆提舎願生偈』（正式名『無量寿経優婆提舎願生偈』）の註釈書である。