What does the poem raft mean?

Biography of Poetry was first written by He, and it lived around 1637.

Preface to Poetry Raft was written after discussing poetry with friends twenty years ago. It was considered a raft, so it was called Poetry Raft. Today, I don't know who it is. Give up the idea of wanting someone, okay? Although, if you can give up your hope, you can use it. "Deep is sharp, shallow is dew", Xi take the raft as an example? Heqiao magpie, crossing the river, Gebei Longyan, throwing it at the economy, taking the raft as a joke? You wade in the river, float in the sea, but you can't see it. He sent you back from the cliff, and you have been away from it ever since. Is it for the raft? For the raft? Don't give up for useless use? If my husband is like this, then my book can be circulated or burned. He Yongxin Yishun knows.

Poetry raft here means:

Raft is just a tool to describe the understanding and learning of poetry (that is, to educate people with poetry)