What is the origin of the idiom "chew one's cud" and when to use it?

The origin of the idiom "chew one's cud" can be traced back to the behavior of ruminant animals such as cows, sheep, and goats. These animals have a unique digestive system that involves chewing, swallowing, and regurgitating their food to aid in digestion. The phrase "chew one's cud" emerged from the observation of this specific behavior. Over time, it gained figurative usage to describe the act of deep contemplation or reflective thinking. It is commonly employed in discussions or situations where individuals need to carefully consider information, ideas, or options before making a decision or forming an opinion.