The earliest document from the blessing of oils seems inside the Apostolic Tradition, an early Christian document normally acknowledged to get dated before 235 CE. Now, consecrating the oils is intently tied to preparation for Holy Saturday’s Easter Vigil, as hundreds are baptized in to the Catholic Church from https://liantong.com.tw/%e6%96%b0%e7%ab%b9%e6%88%bf%e5%b1%8b%e4%ba%8c%e8%83%8e%e8%b2%b8%e6%ac%be%e8%a9%b3%e7%b4%b0%e6%94%bb%e7%95%a5%ef%bc%9a%e6%8f%90%e4%be%9b%e8%b3%87%e9%87%91%e5%bd%88%e6%80%a7%e7%ae%a1%e7%90%86/