'Observe' in the Bible

And ye shall observe the feast of unleavened bread; for in this selfsame day have I brought your hosts out of the land of Egypt: therefore shall ye observe this day throughout your generations by an ordinance for ever.

And ye shall observe this thing for an ordinance to thee and to thy sons for ever.

Wherefore the children of Israel shall keep the sabbath, to observe the sabbath throughout their generations, for a perpetual covenant.

Observe thou that which I command thee this day: behold, I drive out before thee the Amorite, and the Canaanite, and the Hittite, and the Perizzite, and the Hivite, and the Jebusite.

And thou shalt observe the feast of weeks, even of the first-fruits of wheat harvest, and the feast of ingathering at the year's end.