why does 切手 mean stamp... is it just me?

okay so i was looking at this letter from japan and i saw the word 切手 and literally my brain stopped. isn't that 'cut' and 'hand'??? like... why is a stamp a cut hand?? am i missing some horrific history here or is my kanji just completely broken lol. wait is this a dumb question to ask on here? i didn't even google it first but now i'm staring at it like... please tell me nobody is cutting hands