'Observe' in the Bible

And why are ye careful about clothing? Observe with attention the lilies of the field, how they grow: they toil not, neither do they spin;

Jesus answered them, "Go and tell John what you hear and observe:

All therefore whatsoever they bid you observe, that observe and do; but do not ye after their works: for they say, and do not.

'Whenever, therefore, ye may see the abomination of the desolation, that was spoken of through Daniel the prophet, standing in the holy place (whoever is reading let him observe)

He said, "Go into the city to a certain man and tell him, 'The Teacher says, "My time is near. I will observe the Passover with my disciples at your house."'"

Teaching them to observe all things whatsoever I have commanded you: and, lo, I am with you alway, even unto the end of the world. Amen.