The first clause is casuistic and the second apodictic. Here are instructions concerning the return of an enemy's ox or donkey. The law doesn't say so. Casuistic law gives the principle by example and implicitly covers all animals. If the Bible gave specific laws for everything, we would need an entire library to fill all the volumes.
Case law provides a principle that has a wide range of application.
As you encounter proverbial passages about child rearing, social ethics, and other practical principles, remember to examine the passages in light of casuistic and apodictic reasoning.