Duke Wen of Jin (晉文公; Jìn Wén Gōng, 697–628 BC) was the ruler of the state of Jin from 636-628 BC. He is remembered in the histories for having spent much of his life in exile from his home following a breakdown in relations with his father. Upon his assumption of the Dukedom, the state of Jin expanded and became one of the most powerful in ancient China.
Shunzei here is referring to how the Japanese word for ‘waves’ (nami) is transformed to the word for ‘tears’ (namida) with the addition of voiced ta (da).
The commentators speculate here that Shunzei’s basis for this judgement is a personal preference for the Right’s more negative outlook, as opposed to the positive one of the Left.
The suggestion here is that the poem conveys too much expectation that event will work out as the poet wishes, and so lacks the nervousness which a proper lover should display.
蓬莱山 a mystical land in Chinese mythology, said to be home to the Eight Immortals. Qin Shihuang sought it in his later years, in search of the elixir of immortality.
This poetry competition took place in 1049, on the ninth day of the Eleventh Month. It was a fifteen round contest held at the court of the Emperor Go-Reizei. Sagami’s poem, on the topic of Love, was presented in Round 14.