The earliest report from the blessing of oils seems during the Apostolic Tradition, an early Christian doc usually acknowledged to get dated prior to 235 CE. Now, consecrating the oils is closely tied to preparing for Holy Saturday’s Easter Vigil, as thousands are baptized in the Catholic Church from https://liantong.com.tw/%e6%83%b3%e8%be%a6%e7%90%86%e6%96%b0%e7%ab%b9%e6%88%bf%e5%b1%8b%e4%ba%8c%e8%83%8e%e8%b2%b8%e6%ac%be%ef%bc%9f%e8%81%af%e9%80%9a%e8%b2%b8%e6%95%99%e6%82%a8%e5%a6%82%e4%bd%95%e7%b0%a1%e5%96%ae%e7%94%b3/