مُحَمَّدُ بْنُ يَحْيَى عَنْ أَحْمَدَ بْنِ مُحَمَّدٍ عَنِ الْحُسَيْنِ بْنِ يَزِيدَ النَّوْفَلِيِّ عَنِ الْحُسَيْنِ بْنِ أَعْيَنَ أَخُو مَالِكِ بْنِ أَعْيَنَ قَالَ سَأَلْتُ أَبَا عَبْدِ اللَّهِ (عليه السلام) عَنْ قَوْلِ الرَّجُلِ لِلرَّجُلِ جَزَاكَ اللَّهُ خَيْراً مَا يَعْنِي بِهِ فَقَالَ أَبُو عَبْدِ اللَّهِ (عليه السلام) إِنَّ خَيْراً نَهَرٌ فِي الْجَنَّةِ مَخْرَجُهُ مِنَ الْكَوْثَرِ وَ الْكَوْثَرَ مَخْرَجُهُ مِنْ سَاقِ الْعَرْشِ عَلَيْهِ مَنَازِلُ الْأَوْصِيَاءِ وَ شِيعَتِهِمْ عَلَى حَافَتَيْ ذَلِكَ النَّهَرِ جَوَارِي نَابِتَاتٌ كُلَّمَا قُلِعَتْ وَاحِدَةٌ نَبَتَتْ أُخْرَى سُمِّيَ بِذَلِكَ النَّهَرُ وَ ذَلِكَ قَوْلُهُ تَعَالَى فِيهِنَّ خَيْراتٌ حِسانٌ فَإِذَا قَالَ الرَّجُلُ لِصَاحِبِهِ جَزَاكَ اللَّهُ خَيْراً فَإِنَّمَا يَعْنِي بِذَلِكَ تِلْكَ الْمَنَازِلَ الَّتِي قَدْ أَعَدَّهَا اللَّهُ عَزَّ وَ جَلَّ لِصَفْوَتِهِ وَ خِيَرَتِهِ مِنْ خَلْقِهِ.
298. Muhammad Bin Yahya, from Ahmad Bin Muhammad, from Al-Husayn Bin Yazeed Al-Nawfaly, from Al-Husayn Bin Ayn the brother of Malik Bin Ayn who said: I asked Abu Abdullah  about the words which a person would say to another person, ‘جَزَاكَ اللَّهُ خَيْراً’ ‘May Allah (azwj) Reward you with goodness (Khair)’, what is meant by it?’ So Abu Abdullah  said: ‘Khair’ is a river in the Paradise, a tributary from Al-Kawsar. And Al-Kawsar comes out from the Pillar of the Throne around which are houses of the successors , and their  Shites. On the banks of that river maids (Houries) grow. Every time one is taken, another one grows in its place, and they have been named after that river (Khair). And that is the Statement of the High (azwj): “[5:70] In them are goodly things (Khair), beautiful ones”. So if the man says to his companion, ‘May Allah (azwj) Reward you with goodness (Khaira)’, it means by that those dwellings which Allah (azwj) Mighty and Majestic has Prepared for His (azwj) elite, and the good ones from His (azwj) creatures’.