Do not speak in the hearing of a fool, for he will despise the good sense of your words.
In context
7for he is the sort who keeps count within himself. “Eat and drink,” he says to you, but his heart is not with you. 8You will vomit up the morsel you have eaten and waste your pleasant words. 9Do not speak in the hearing of a fool, for he will despise the good sense of your words. 10Do not move an ancient boundary stone or enter the fields of the fatherless, 11for their Redeemer is strong; he will plead their case against you.
