Holy Manna is the tune written for “Brethren, We Have Met To Worship,” which is one of the oldest American folk hymns. Holy Manna was originally published by William Moore in Columbian Harmony, a shape-note tune book, in 1829.

Our hymnal uses the tune for “As We Gather At Your Table.”
https://hymnary.org/hymn/WORS2011/831

Played by Canaan’s Crossing

Shape-note singing from San Antonio, Texas