Psalm 17:14 has some difficulties in the Hebrew text. Still, the basic meaning is clear. David is describing his enemies as those whose portion or inheritance is restricted to this present life. Their troubles are few, and their pleasures are many. They have rejected the Lord and his anointed. This is in contrast to David saying in the previous psalm that the Lord was his portion (Psalm 16:5).
14 from men by your hand, O LORD, from men of the world whose portion is in this life. You fill their womb with treasure; they are satisfied with children, and they leave their abundance to their infants.