'Observe' in the Bible

‘Observe the Sabbath day to keep it holy (set apart, dedicated to God), as the Lord your God commanded you.

You shall remember [with thoughtful concern] that you were a slave in the land of Egypt, and that the Lord your God brought you out of there with a mighty hand and by an outstretched arm; therefore the Lord your God has commanded you to observe the Sabbath day.

“Observe the month of Abib and celebrate the Passover to the Lord your God, for in the month of Abib the Lord your God brought you out of Egypt by night.

“You shall celebrate the Feast of Booths (Tabernacles) seven days, when you have gathered in [the grain] from your threshing floor and [the wine] from your wine vat.