'Observing' in the Bible

The Israelites must keep the Sabbath by observing the Sabbath throughout their generations as a perpetual covenant.

They offer burnt sacrifices to the Lord every morning and every evening, along with fragrant incense. They arrange the Bread of the Presence on a ritually clean table and light the lamps on the gold lampstand every evening. Certainly we are observing the Lord our God's regulations, but you have rejected him.

For observing the festival is a requirement for Israel; it is an ordinance given by the God of Jacob.

Ariel is as good as dead -- Ariel, the town David besieged! Keep observing your annual rituals, celebrate your festivals on schedule.