So once in every year we throng Upon a day apart, To praise the Lord with feast and song In thankfulness of heart.

The stanza evokes the annual rhythm of communal worship: once a year, people gather in unusually large numbers (“throng”) for a special holy day marked by music, celebration, and gratitude. The emphasis falls less on doctrine than on shared practice—feast and song as outward signs of inward “thankfulness of heart.” Read broadly, it reflects a tradition of setting aside a designated day for collective remembrance and praise, suggesting that gratitude is both personal and civic, expressed through ritual, fellowship, and public joy.