The soul and the mouth are two different things. Which one is man trying to fill? All his attention is given to his mouth, yet his soul is the enduring part of him and the part that it is more important to satisfy.
Covetousness is an insatiable appetite. Constantly it makes false promises to us, telling us that the next possession will bring peace, rest, satisfaction, setting us free from the treadmill of constantly obtaining more.
Man thinks he understands himself; he thinks that he knows what it takes to satisfy himself, and yet he never reaches the point where he is content. His soul does not benefit from all his labour. Why does he give so little attention to it? Why does he leave the soul to starve while filling the stomach? Why does he make such great mistakes about his needs? Because having rebelled against God and having come under condemnation and lost spiritual life, he knows that he cannot satisfy his soul without returning to God, humbling himself and coming in repentance and asking for forgiveness, and that he is unwilling to do.