During the Nara period when Buddhist deities were believed to protect the nation, Buddhist scriptures were copied as a national project, but by the Heian period when Jodo-shiso (Pure Land Buddhism) prevailed, they were copied by individuals who wished for their prayers to be fulfilled.
仏教経典を書写する写経は国家仏教中心の奈良時代には官営事業として行われていたが、平安時代には浄土思想が普及し、個人的な祈願成就を目的に行われるようになった。