Chewing the cud

Saw these cows on lovely walk to Walberswick.
Psalm 1 continues: "and who meditates on it (the law of the LORD) day and night."
To meditate is to think over something; to chew it over; to ponder it. As we ponder what God's law says it shapes how we think and behave.
From wiki
Cud is a portion of food that returns from a ruminant's stomach to the mouth to be chewed for the second time. More accurately, it is a bolus of semi-degraded food regurgitated from the reticulorumen of a ruminant. Cud is produced during the physical digestive process of rumination. The idiomatic expression chewing one's cud means meditating or pondering; similar expressions such as "he chewed that over for a bit", or "chew on that!" likely have the same derivation.