'Observe' in the Bible
“Now, let the sons of Israel observe the Passover at its appointed time.
On the fourteenth day of this month, at twilight, you shall observe it at its appointed time; you shall observe it according to all its statutes and according to all its ordinances.”
But there were some men who were unclean because of the dead person, so that they could not observe Passover on that day; so they came before Moses and Aaron on that day.
“Speak to the sons of Israel, saying, ‘If any one of you or of your generations becomes unclean because of a dead person, or is on a distant journey, he may, however, observe the Passover to the Lord.
In the second month on the fourteenth day at twilight, they shall observe it; they shall eat it with unleavened bread and bitter herbs.
They shall leave none of it until morning, nor break a bone of it; according to all the statute of the Passover they shall observe it.
But the man who is clean and is not on a journey, and yet neglects to observe the Passover, that person shall then be cut off from his people, for he did not present the offering of the Lord at its appointed time. That man will bear his sin.
‘But when you unwittingly fail and do not observe all these commandments, which the Lord has spoken to Moses,
‘Then on the fifteenth day of the seventh month you shall have a holy convocation; you shall do no laborious work, and you shall observe a feast to the Lord for seven days.