It seems that Sankashu is based on a collection of poetry selected by Saigyo himself in his lifetime and enhanced by someone in later years, so its relation with "Sankashinchushu" and "Saigyo Shonin shu" compiled by Saigyo himself is worth noting.
西行生前の撰を後人が増補したと見られ、西行の自撰なる『山家心中集』や、『西行上人集』との関連が注目される。