'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;

teaching them to observe all things whatsoever I have enjoined you. And behold, I am with you all the days, until the completion of the age.

And he said to them, Well do ye set aside the commandment of God, that ye may observe what is delivered by yourselves to keep.

And as they passed through the cities they instructed them to observe the decrees determined on by the apostles and elders who were in Jerusalem.

But concerning those of the nations who have believed, we have written, deciding that they should observe no such thing, only to keep themselves both from things offered to idols, and from blood, and from things strangled, and from fornication.

Ye observe days and months and times and years.