کَلَّا لَوْ تَعْلَمُوۡنَ عِلْمَ الْیَقِیۡنِ

Yes certainly, had you truly believed, you would not have loved wealth.

Tafsir al-Tabari                                                         تفسیر الطبری                                

أَيُّهَا النَّاسُ، لَوْ تَعْلَمُونَ أَيُّهَا النَّاسُ عِلْمًا يَقِينًا، أَنَّ اللَّهَ بَاعِثُكُمْ يَوْمَ الْقِيَامَةِ مِنْ بَعْدِ مَمَاتِكُمْ، مِنْ قُبُورِكُمْ، مَا أَلْهَاكُمُ التَّكَاثُرُ عَنْ طَاعَةِ اللَّهِ رَبِّكُمْ، وَلَسَارَعْتُمْ إِلَى عِبَادَتِهِ

i.e. O people, had you truly believed that indeed Allah Almighty will resurrect you from your graves after your death on the Day of Judgment then despite whatever had kept you negligent from Allah’s obedience, you would still have hastened towards His worship.

عَنْ قَتَادَةَ، {كَلَّا لَوْ تَعْلَمُونَ عِلْمَ الْيَقِينِ} [التكاثر: 5] كُنَّا نُحَدِّثُ أَنَّ عِلْمَ الْيَقِينِ، أَنْ يَعْلَمَ أَنَّ اللَّهَ بَاعِثُهُ بَعْدَ الْمَوْتِ

Sayyiduna Qatadah – may Allah be pleased with him – is reported to have commented on the verse:  We used to discuss that for one “to truly believe” is to know with certainty that Allah Almighty will definitely resurrect him after death.

Tafsir Al-Tabari (Tafsir Ibn Jareer / Jame’ al-Bayaan fi Taweel al-Quraan) of Imam Abu Ja’far Muhammad ibn Jareer al-Tabri t D. 310 A.H.