蘭室の友に交りて麻畝の性と成る - You have associated with a friend in the orchid room and have become as straight as mugwort growing among hemp.

本文
鳩 化して鷹と為り 雀 変じて蛤と為る、悦しきかな 汝 蘭室の友に交りて麻畝の性と成る

立正安国論
（３１頁）
文応元年７月

（１２６０年）

通解（意訳）
古事に「鳩化して鷹となり、雀（福良雀という、雀（すずめ）の形のような貝）が変じて蛤（はまぐり）となる」とあるように、人は善き友（善知識）と交わることで、より善い人間になることができる。
悦ばしいことに、あなたは蘭室の友（蘭の香りのように人徳の薫り高い人）に交わって感化されて、蓬（よもぎ）のように曲がりがちな性格が、真っ直ぐに育つ麻畑の中に蓬が交わって正されたように、素直で真っ直ぐな性格になれた。

English Gosho
The dove has changed into a hawk, the sparrow into a clam.
How gratifying!
You have associated with a friend in the orchid room and have become as straight as mugwort growing among hemp.

" On Establishing the Correct Teaching for the Peace of the Land "
July, 1260.
"The Writings of Nichiren Daishonin", Vol.1, p. 23
[ --- ] is liberal translation.

Interpretation (liberal translation) 
You were inspired by crossing a friend in the Orchid's breeding room (a person with high virtue like the scent of orchids).
And as your character who was prone to bend like a wormwood was crossed and straightened in the hemp field that grew up straight, you were made a straightforward personality.

参考文献：
「日蓮大聖人御書全集」
「御書をひもとく」
「英語で学ぶ御書」
第三文明社
Bibliography :
"The Writings of Nichiren Daishonin"
"The Record of The Orally Transmitted Teachings"