'Sentinel' in the Bible

While I was watching in my mind's visions on my bed, a holy sentinel came down from heaven.

As for the king seeing a holy sentinel coming down from heaven and saying, 'Chop down the tree and destroy it, but leave its taproot in the ground, with a band of iron and bronze around it, surrounded by the grass of the field. Let it become damp with the dew of the sky, and let it live with the wild animals, until seven periods of time go by for him' --