Exodus 13:21 tells, "And the LORD (Yahweh) went before them by day in a piller of cloud to lead the way, and by night in a piller of fire to give them light....." This was a sign of His presence in the desert.(Exodus 40:38)
A pillar of cloud which descended upon the Tent of Meeting.
For the ancient Israelites, blood wast the sign of life itself.
The sign of life.
Yes
One official definition for the word sign is "an object, quality, or event whose presence or occurrence indicates the probable presence or occurrence of something else."
The presence of the first spirit.
Curtsey or bow as a sign of respect.
It can be a sign of mildew or mold.
In many religions, a sign of the covenant is a physical symbol or ritual that represents a sacred agreement or promise between humans and the divine. It can vary depending on the specific religious tradition, such as circumcision in Judaism or baptism in Christianity.
self-heating or pyrophoric materials
When they are sick or stressed. It is also a common sign of a parasititic presence.
Albuminuria