The Kyorai-shô is a book of haikai commentary collated by ex-samurai turned Bashô disciple Kyorai, and although it is quite tough going even in a modern, printed edition (let alone a dakuten-free monster like this), it's full of human drama, like this early passage where Kyorai and his fellow disciple Bonchô, with whom he co-edited the Monkey's Rain-cape (Saru mino) anthology, bicker about their editorial duties:

此木戸や鎖のさゝれて冬の月　其角

猿蓑撰の時に此句書おくり冬の月霜の月置わつらひ侍るよし聞ゆ　衆議冬の月による　先師曰其角か冬霜に煩ふへき句にもあらすとて冬の月に定め入集させられける　はしめは文字つまりて柴戸とよめたり　然るに出版の後大津より先師の文に柴の戸にあらす此木戸なり　かゝる秀逸は一句も大切なり　たとへ出版におよふともいそき改むへしとなり　凡兆曰柴の戸此木戸させる勝劣なし　去来曰此月を柴の戸に寄て見れは尋常の気色なり　是を城門にうつして見れは其風情あはれに物凄きいかはかりなし　実も其角か冬霜にわつらへるもことはりなり

Which is to say:

This castle gate, chained shut / Winter moon -- Kikaku

This poem was sent in while we were choosing poems for the Monkey's Rain-cape, and I heard that he couldn't decide if it should be "winter moon" or "November" ["moon of frost"]. We all agreed that "winter moon" was better. Bashô was like, "Eh, it isn't like this is such a great 'ku that Kikaku would care anyway," and settled on "winter moon".

[Also,] at first we read the first two characters as one: "brushwood [fence] gate" (柴戸). But after we went to press, we got a letter from Bashô, who was in Ōtsu at the time. "It's not 'brushwood gate', it's 'this castle gate' (此木戸)," he said. "Every single line matters with brilliance like this. Fix it quickly, even if you have to republish." Bonchô was all, "Changing 'brushwood gate' to 'this castle gate' won't even make a difference," but I was like, "You put the moon up against the brushwood fence gate, and it's just another rustic scene. But shine it on a castle gate, and the aware is off the charts. Of course Kikaku would care whether it was "winter moon" or "November".

It is not recorded whether Bonchô, at this point, actually punched Kyorai, or just rolled his eyes.

Some people attribute Kyorai's strong opinion here partly to nostalgia for his castle-heavy military life, but even putting that aside, Japanese poems about tumbledown huts outnumber those about castles by a hojillion to one. For variety's sake alone you have to prefer the castle interpretation. Also, who chains their brushwood fence shut? Someone could just kick it open.

Another popular interpretation of the poem is that the 木戸 cited is not a castle gate, but rather one of the gates throughout Edo that were closed after curfew, and the narrator is not a mysterious figure standing before a silent fortress at midnight, but simply a drunkard who failed to think ahead.

Anyway, this problem could have been solved if Kikaku had written kono with kana (この) instead of kanji (此), and in subsequent editions of the Rain-cape, that's exactly what they did. (It's in the middle, directly to the left of the gutter.)