The effect of Istighfar

وَيُمْدِدْكُم بِأَمْوَالٍ وَبَنِينَ وَيَجْعَل لَّكُمْ جَنَّاتٍ وَيَجْعَل لَّكُمْ أَنْهَارًا

And help you with wealth and sons, and make for you gardens, and make for you rivers.