تُؤْثِرُ فِلْسًا تُوعِيهِ عَلَى ذِكْرٍ تَعِيهِ
You prefer putting away a small coin to retaining a meaningful reminder.
Fils is a small coin. Tūʿīhi means to store or preserve it, while taʿīhi means to understand and retain the admonition. The related sounds reinforce the comparison.
The point is not that all saving is wrong. It is the misplaced priority of a minor possession over valuable moral understanding.