The earliest file on the blessing of oils seems during the Apostolic Tradition, an early Christian doc generally acknowledged to be dated in advance of 235 CE. Now, consecrating the oils is closely tied to planning 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/