Bible Dictionary
OBSERVE
To observe means to take heed, keep, watch, regard, or follow. In Scripture it may refer to keeping a feast or law, remembering a saying, watching over someone, or giving attention to something.
Biblical Usage
Biblical translations use observe for keeping a feast or law, remembering a saying, watching people, regarding vanities, caring for someone, and protecting someone. “The kingdom of God cometh not with observation” means it does not come in a manner that can simply be observed, though the exact force is disputed.