Muslim, Abu Dawud and An-Nasa'i, all recorded from Anas that he said,

"While we were with the Messenger of Allah in the Masjid, he dozed off into a slumber. Then he lifted his head smiling. We said, `O Messenger of Allah! What has caused you to laugh' He said, Verily, a Surah was just revealed to me. Then he recited,

إِنَّا أَعْطَيْنَاكَ الْكَوْثَرَ

فَصَلِّ لِرَبِّكَ وَانْحَرْ

إِنَّ شَانِيَكَ هُوَ الاٌّبْتَرُ

Verily, We have granted you Al-Kawthar.

Therefore turn in prayer to your Lord and sacrifice.

For he who hates you, he will be cut off.

Then he said,

Do you all know what is Al-Kawthar?

We said, `Allah and His Messenger know best.'

He said,

فَإِنَّهُ نَهَرٌ وَعَدَنِيهِ رَبِّي عَزَّ وَجَلَّ عَلَيْهِ خَيْرٌ كَثِيرٌ

هُوَ حَوْضٌ تَرِدُ عَلَيْهِ أُمَّتِي يَوْمَ الْقِيَامَةِ

انِيَتُهُ عَدَدُ النُّجُومِ فِي السَّمَاءِ

فَيُخْتَلَجُ الْعَبْدُ مِنْهُمْ فَأَقُولُ رَبِّ إِنَّهُ مِنْ أُمَّتِي

فَيَقُولُ إِنَّكَ لَا تَدْرِي مَا أَحْدَثَ بَعْدَك

Verily, it is a river that my Lord, the Mighty and Majestic, has promised me and it has abundant goodness.

It is a pond where my Ummah will be brought to on the Day of Judgement.

Its containers are as numerous as the stars in the sky.

Then a servant of Allah from among them will be (prevented from it) and I will say:

"O Lord! Verily, he is from my Ummah (followers)."

Then He (Allah) will say:

"Verily, you do not know what he introduced (or innovated) after you."

This is the wording of Muslim.

Ahmad recorded this Hadith from Muhammad bin Fudayl, who reported from Al-Mukhtar bin Fulful, who reported it from Anas bin Malik.

Imam Ahmad also recorded from Anas that the Messenger of Allah said,

دَخَلْتُ الْجَنَّةَ فَإِذَا أَنَا بِنَهْرٍ حَافَتَاهُ خِيَامُ اللُّوْلُوِ

فَضَرَبْتُ بِيَدِي إِلَى مَا يَجْرِي فِيهِ الْمَاءُ فَإِذَا مِسْكٌ أَذْفَرُ

قُلْتُ مَاهَذَا يَا جِبْرِيلُ

قَالَ هَذَا الْكَوْثَرُ الَّذِي أَعْطَاكَهُ اللهُ عَزَّ وَجَل

I entered Paradise and I came to a river whose banks had tents made of pearls. So I thrust my hand into its flowing water and found that it was the strongest (smell) of musk. So I asked, "O Jibril! What is this"

He replied,

"This is Al-Kawthar which Allah, the Mighty and Majestic has given you."

Al-Bukhari recorded this in his Sahih, and so did Muslim, on the authority of Anas bin Malik. In their version Anas said, "When the Prophet was taken up to the heaven, he said,

أَتَيْتُ عَلَى نَهْرٍ حَافَتَاهُ قِبَابُ اللُّوْلُوِ الْمُجَوَّفِ فَقُلْتُ مَا هَذَا يَا جِبْرِيلُ قَالَ هَذَا الْكَوْثَر

I came to a river whose banks had domes of hollowed pearl. I said:"O Jibril! What is this"

He replied:

"This is Al-Kawthar."

This is the wording of Al-Bukhari.

Ahmad recorded from Anas that a man said,

"O Messenger of Allah! What is Al-Kawthar?"

He replied,

هُوَ نَهْرٌ فِي الْجَنَّةِ أَعْطَانِيهِ رَبِّي

لَهُوَ أَشَدُّ بَيَاضًا مِنَ اللَّبَنِ وَأَحْلَى مِنَ الْعَسَلِ

فِيهِ طُيُورٌ أَعْنَاقُهَا كَأَعْنَاقِ الْجُزُر

It is a river in Paradise which my Lord has given me. It is whiter than milk and sweeter than honey. There are birds in it whose necks are (long) like carrots.

Umar said, "O Messenger of Allah! Verily, they (the birds) will be beautiful."

The Prophet replied,

اكِلُهَا أَنْعَمُ مِنْهَا يَا عُمَر

The one who eats them (i.e., the people of Paradise) will be more beautiful than them, O `Umar.

Al-Bukhari recorded from Sa`id bin Jubayr that Ibn Abbas said about Al-Kawthar,

"It is the good which Allah gave to him (the Prophet)."

Abu Bishr said,

"I said to Sa`id bin Jubayr, `Verily, people are claiming that it is a river in Paradise."'

Sa`id replied,

`The river which is in Paradise is part of the goodness which Allah gave him."'

Al-Bukhari also recorded from Sa`id bin Jubayr that Ibn Abbas said,

"Al-Kawthar is the abundant goodness."

This explanation includes the river and other things as well. Because the word Al-Kawthar comes from the word Kathrah (abundance) and it (Al-Kawthar) linguistically means an abundance of goodness. So from this goodness is the river (in Paradise).

Imam Ahmad recorded from Ibn Umar that the Messenger of Allah said,

الْكَوْثَرُ نَهْرٌ فِي الْجَنَّةِ حَافَتَاهُ مِنْ ذَهَبٍ وَالْمَاءُ يَجْرِي عَلَى اللُّوْلُوِ

وَمَاوُهُ أَشَدُّ بَيَاضًا مِنَ اللَّبَنِ وَأَحْلَى مِنَ الْعَسَل

Al-Kawthar is a river in Paradise whose banks are of gold and it runs over pearls. Its water is whiter than milk and sweeter than honey.

This Hadith was recorded in this manner by At-Tirmidhi, Ibn Majah, Ibn Abi Hatim and Ibn Jarir.

At-Tirmidhi said, "Hasan Sahih."

Then Allah says,

فَصَلِّ لِرَبِّكَ وَانْحَرْ