Ibn 'Abbas reported that Allah's Messenger (ﷺ) came to privy and I placed for him water for ablution, When he came out he said: Who placed it here? And in a version of Zuhair they (the Companions) said, and in the version of Abu Bakr (the words are): I said: It is Ibn 'Abbas (who has done that), whereupon he (the Holy Prophet) said: May Allah grant him deep understanding of religion.
Source: sunnah.com
Other translations
Arabic
حَدَّثَنَا زُهَيْرُ بْنُ حَرْبٍ، وَأَبُو بَكْرِ بْنُ النَّضْرِ قَالاَ حَدَّثَنَا هَاشِمُ بْنُ الْقَاسِمِ، حَدَّثَنَا وَرْقَاءُ بْنُ عُمَرَ الْيَشْكُرِيُّ، قَالَ سَمِعْتُ عُبَيْدَ اللَّهِ بْنَ أَبِي يَزِيدَ، يُحَدِّثُ عَنِ ابْنِ عَبَّاسٍ، أَنَّوسلم أَتَى الْخَلاَءَ فَوَضَعْتُ لَهُ وَضُوءًا فَلَمَّا خَرَجَ قَالَ " مَنْ وَضَعَ هَذَا " . فِي رِوَايَةِ زُهَيْرٍ قَالُوا . وَفِي رِوَايَةِ أَبِي بَكْرٍ قُلْتُ ابْنُ عَبَّاسٍ . قَالَ " اللَّهُمَّ فَقِّهْهُ " .
sunnah.com