The chalking of the Door is typically done on January 6th on the Feast of the Epiphany and celebrates the revealing of Christ to the world in three events…
From the excellent blog, “The Homely Hours” – a traditional family liturgy performed upon the Feast of the Epiphany:
“This short liturgy is a way of yearly marking our homes, usually at the front or main entrance, with sacred signs and symbols to intentionally set our homes apart as places of Christian hospitality, as safe and peaceful outposts of the Kingdom of God in the world, as habitations of healing and rest. We again invite God’s presence into our homes and ask His blessing upon all those who live, work, or visit throughout the coming year.”
“C+M+B” has a dual significance: it represents the names of the Three Wise Men (Magi, or Sacred Kings), as traditionally named by the Church: Caspar, Melchior, and Balthasar; and it also stands for Christus Mansionem Benedicat, Latin for “Christ, this house Bless.” It is flanked by the numbers representing the year: this year, it would read
20 + C + M + B + 19
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