يَوْمَ لَا يَنفَعُ مَالٌ وَلَا بَنُونَ ۝ إِلَّا مَنْ أَتَى اللَّهَ بِقَلْبٍ سَلِيمٍ

These verses describe the Day of Judgment when worldly attachments and achievements will be meaningless. Wealth and children - two things people often rely on for security and happiness in this world - will provide no benefit on that Day. The only thing that will matter is coming to Allah with a "sound heart" (qalb salim). A sound heart is one that is free from spiritual diseases like pride, envy, hatred, and hypocrisy; it's pure in its devotion to Allah, sincere in its intentions, and clean from the corruption of sins. This teaches that worldly possessions and relationships, while important in this life, cannot save us in the afterlife; that spiritual purification should be our primary concern; that the heart's condition determines our ultimate success or failure; and that we should invest more in purifying our hearts than in accumulating wealth or even in family relationships that don't lead us closer to Allah.