Deuteronomy 31:10
And Moses commanded them, saying, At the end of every seven years, in the solemnity of the year of release, in the feast of tabernacles,
Isaiah 30:29
Ye shall have a song, as in the night when a holy solemnity is kept; and gladness of heart, as when one goeth with a pipe to come into the mountain of the LORD, to the mighty One of Israel.