The phrase "marriage feast" refers to a celebration or party that takes place after a wedding ceremony, where friends and family come together to eat, drink, and celebrate the marriage of a couple. Full definition
The whole message is a nuptial one — the whole plan from «the beginning» (Gen 1:1, John 1:1) to the glorious Marriage Feast of the Lamb (Rev 19:9) is a message that is also written into the Incarnation, and also, awesomely, into our own lived experience. (faith.org.uk)
When the property owners and businessmen would not come, the king said to his servants, «Go therefore to the thoroughfares, and invite to the marriage feast as many as you find.» (religion-online.org)
It is thus apt that just behind the Holy Rood, in the mosaic behind the baldachin, we are shown the holy army of martyrs who robes have been washed white in the blood of the Lamb and who thus are called to his marriage feast. (faith.org.uk)