Mystery solved! Strange seal is a Buddhist seal, presumably from a temple
Just the other day I posted this mysterious letter that was labelled "Oda Nobunaga" in an auction listing, and the name signature was legible enough to identify as indeed saying "Nobunaga".
It drew my attention because the seal is not Tenka Fubu, and I have no idea what it was at first. Well, I've identified the seal now. It's a Buddhist "Three Treasures seal".
I wasn't able to find a version of it that looks exactly like the one printed on the paper, but there's enough line similarities between the ones I did find and the mysterious seal, that I'm confident enough to say that it's indeed a variation of that very same seal.
The text that is inscribed says: 佛法僧宝 (buppousoubou)
This means: "The treasures: the Buddha, the Dharma, and the Sangha (monks)"
This might be some sort of document awarding a grant to a certain temple, or a statement of offering, and was stamped with the temple's seal. Unfortunately this is not something that I was able to find much info on. Temples do have seals that they apparently stamp on paperwork or sutras as proof of pilgrimage or offerings, but I couldn't find any other Sengoku period examples of this being done on a samurai document.
Without knowing what the letter actually says, it's hard to tell what's going on in here.
The auctioneer does not have a transcript of the letter's content, and I have no idea where it went now (presumably already bought by someone). So unless this text eventually turns up again elsewhere, with experts providing the analysis, I'm stumped.








