"Fire came out from the presence of the LORD and consumed the burnt offering and the fat portions on the altar. And when all the people saw it, they shouted for joy and fell facedown." (Leviticus 9:24)
On the eighth day after the ordination, Aaron and his sons begin their ministry. Moses tells Aaron: come to the altar and sacrifice your sin offering and your burnt offering and make atonement for yourself and the people. Aaron approaches the altar, slaughters his own sin offering first - the priest must be purified before he can purify others - then offers the burnt offerings and fellowship offerings for the people. After the offerings Moses and Aaron bless the people and the glory of the LORD appears to all of them. Then: Fire came out from the presence of the LORD and consumed the burnt offering and the fat portions on the altar. And when all the people saw it, they shouted for joy and fell facedown.
The divine fire that consumes the altar offering is the sign of divine acceptance, the visible confirmation that God has received what has been offered. The people shout and prostrate: both the vertical cry and the physical bowing express the full response of a creature before its Creator. The Catechism identifies this pattern of divine initiative and human response as the structure of all genuine liturgy: God acts first, reveals himself, and the community responds in praise and adoration (CCC 1083). Every Mass follows this pattern: God offers himself; the community prostrates in thanksgiving.
Brothers and sisters, fire came out from the presence of the LORD. The divine acceptance of the offering produced a visible sign that the people could see. Ask God to make his acceptance of your worship visible to you: not always in dramatic signs, but in the interior confirmation of the Spirit that what you have offered has been received with favour.
Lord God, let your glory appear to your people. Send the fire of your Spirit to consume what we offer on the altar of prayer and worship. And when we see it, let us shout for joy and fall facedown. Through Christ our Lord. Amen.