Narrated Abdullah ibn Mughaffal: Abdullah heard his son praying to Allah: O Allah, I ask Thee a white palace on the right of Paradise when I enter it. He said: O my son, ask Allah for Paradise and seek refuge in Him from Hell-Fire, for I heard the Messenger of Allah (ﷺ) say: In this community there will be some people who will exceed the limits in purification as well as in supplication.
Source: sunnah.com
Other translations
Arabic
حَدَّثَنَا مُوسَى بْنُ إِسْمَاعِيلَ، حَدَّثَنَا حَمَّادٌ، حَدَّثَنَا سَعِيدٌ الْجُرَيْرِيُّ، عَنْ أَبِي نَعَامَةَ، أَنَّ عَبْدَ اللَّهِ بْنَ مُغَفَّلٍ، سَمِعَ ابْنَهُ، يَقُولُ اللَّهُمَّ إِنِّي أَسْأَلُكَ الْقَصْرَ الأَبْيَضَ عَنْ يَمِينِ الْجَنَّةِ، إِذَا دَخَلْتُهَا . فَقَالَ أَىْ بُنَىَّ سَلِ اللَّهَ الْجَنَّةَ وَتَعَوَّذْ بِهِ مِنَ النَّارِ فَإِنِّي سَمِعْتُ رَسُولَ اللَّهِ صلى الله عليه وسلم يَقُولُ " إِنَّهُ سَيَكُونُ فِي هَذِهِ الأُمَّةِ قَوْمٌ يَعْتَدُونَ فِي الطُّهُورِ وَالدُّعَاءِ " .
sunnah.com