Meaning of “parler par figure”

Question

« Que fais-tu Patachou? »

Il est au fond du jardin. Il est tourné vers la maison et, de temps en temps, il pousse un petit cri. Il écoute ; puis il rit.

« Je fais le poète ! me repond-il. Cela n'est pas bien difficile. Dès que j'ai dit un mot, on me donne la rime. Mais il faut crier assez fort. C'est l'écho, c'est la poésie... »

« Tu ne crois pas si bien dire, Patachou ; et, sans le savoir dire, tu parles par figure.

This is from "Patachou" by Tristan Dreme. I do not understand the meaning of the sentences below.

1. Tu ne crois pas si bien dire,
2. tu parles par figure.

I am so glad if somebody kindly teach me.

Answer 1

Tu ne crois pas si bien dire is a common phrase that means "You are definitely right, even more than you could imagine". You have to understand this phrase as "you don't believe that you are so right when you are saying this".

As for figure, I understand it here as as figure de style, which has the same meaning as figure of speech in English. As Patachou tries to speak like a poet, he uses figures of speech (eg metaphors) without even knowing it.