החכם עיניו בראשו
Another example of a Halacha that is alluded to in Kohelet, comes from the words, החכם עיניו בראשו, “the wise man has his eyes in his head.”
This is a reference to the problem we may be confronted with, regarding planning a meal and making the appropriate before and after Bracha. We sometimes get in trouble when we decide to eat foods that we were unaware of, at the beginning of the meal. For example, we made a blessing on an apple, not taking into account the dates and figs that he would also eat. He should have made the Bracha on the Seven Species, and should have paid better attention.
Another example would be making blessings on specific foods, and only afterwards, noticing some delicious looking bread. He will only then decide to wash and make המוציא that would have exempted him from all of these Brachot.
Kohelet is telling us that a wise man has his eyes in his head, and anticipates before sitting down for a meal, all of the potential foods that he may eat.