Sunan Ibn Majah
Sunan Ibn Majah 741
حَدَّثَنَا جُبَارَةُ بْنُ الْمُغَلِّسِ، حَدَّثَنَا عَبْدُ الْكَرِيمِ بْنُ عَبْدِ الرَّحْمَنِ، عَنْ أَبِي إِسْحَاقَ، عَنْ عَمْرِو بْنِ مَيْمُونٍ، عَنْ عُمَرَ بْنِ الْخَطَّابِ، قَالَ قَالَ رَسُولُ اللَّهِ ـ صلى الله عليه وسلم ـ " مَا سَاءَ عَمَلُ قَوْمٍ قَطُّ إِلاَّ زَخْرَفُوا مَسَاجِدَهُمْ " .
Unreviewed translation. All hadiths in this collection are available in five languages. Titles and introductions may remain in Arabic.
Jubarah ibn al-Mughallis narrated to us: 'Abd al-Karim ibn 'Abd al-Rahman narrated to us, from Abu Ishaq, from 'Amr ibn Maymun, from 'Umar ibn al-Khattab, who said: The Messenger of Allah (peace and blessings be upon him) said: ‘Whenever a people's deeds become bad, they adorn their mosques.’
Notes and open questions — unreviewed
The verb زَخْرَفُوا refers to embellishing or ornamenting the mosques.