The earliest report with the blessing of oils seems within the Apostolic Custom, an early Christian document commonly acknowledged to generally be dated just before 235 CE. Currently, consecrating the oils is intently tied to preparation for Holy Saturday’s Easter Vigil, as hundreds are baptized in the Catholic Church 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/