St Dometius healing oil
The St Dometius healing oil is dedicated to St Dometius of Persia. He died in 363 and is venerated as a Christian martyr and saint. According to tradition, he was martyred by lapidation during the reign of Julian the Apostate with two companions. He was killed at Nisibis in Mesopotamia.
Dometius of Persia was depicted in an 8th-century fresco in the church of Sancta Maria Antiqua in Rome. This may indicate that there were Greek-speaking monks at Santa Maria Antiqua, as evidenced by these frescoes, which not only depicted Dometius but also Saints Barachisius, Euthymius and Sabas of Palestine.
Tradition of oils
The tradition of anointing with sacred oil is very old indeed. It is used in sacraments and also as a devotional practice. The sick person is invited to apply oil on the part of their body they want healed. As they do so, they are asked to pray to whomever the oil is dedicated to. The Irish blessings oils do not have miraculous power. It is God who has the power to heal. Applying the oil while praying are important ways for us to express our faith in God’s power. Moreover, by doing so we place our trust in God.