تِلْكَ أُمَّةٌ قَدْ خَلَتْThat was a nation who has passed away,meaning, existed before your time.لَهَا مَا كَسَبَتْ وَلَكُم مَّا كَسَبْتُمْThey shall receive the reward of what they earned and you of what you earn.This Ayah proclaims, Your relationship to the Prophets or righteous people among your ancestors will not benefit you, unless you perform good deeds that bring about you religious benefit. They have their deeds and you have yours.وَلَا تُسْأَلُونَ عَمَّا كَانُوا يَعْمَلُونَAnd you will not be asked of what they used to do. This is why a Hadith proclaims,مَنْ بَطَّأَ بِهِ عَمَلُهُ لَمْ يُسْرِعْ بِهِ نَسَبُهWhoever was slowed on account of his deeds will not get any faster on account of his family lineage