Tafsir Ibn Kathir (abridged)
The Reward of the Believers
When Allah tells us about the state of the people of Hell -- we seek refuge with Allah from that state of punishment, vengeance, burning and chains -- and the garments of fire that have been prepared for them, He then tells us about the state of the people of Paradise -- we ask Allah by His grace and kindness to admit us therein. He tells us:
إِنَّ اللَّهَ يُدْخِلُ الَّذِينَ ءَامَنُواْ وَعَمِلُواْ الصَّـلِحَـتِ جَنَـتٍ تَجْرِى مِن تَحْتِهَا الاٌّنْهَـرُ
(Truly, Allah will admit those who believe and do righteous good deeds, to Gardens underneath which rivers flow,) means, these rivers flow throughout its regions, beneath its trees and palaces, and its inhabitants direct them to go wherever they want.
Continue reading the tafsir of ayahs 23–24