ENOfficial
Narrated AbdurRahman ibn Awf: I heard the Messenger of Allah (ﷺ) say: Allah the Exalted has said: I am Compassionate, and this has been derived from mercy. I have derived its name from My name. If anyone joins it, I shall join him, and if anyone cuts it off, I shall cut him off.
Source: sunnah.com
Other translations
Arabic
حَدَّثَنَا مُسَدَّدٌ، وَأَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ قَالاَ حَدَّثَنَا سُفْيَانُ، عَنِ الزُّهْرِيِّ، عَنْ أَبِي سَلَمَةَ، عَنْ عَبْدِ الرَّحْمَنِ بْنِ عَوْفٍ، قَالَ سَمِعْتُ رَسُولَ اللَّهِ صلى الله عليه وسلم يَقُولُ " قَالَ اللَّهُ أَنَا الرَّحْمَنُ وَهِيَ الرَّحِمُ شَقَقْتُ لَهَا اسْمًا مِنَ اسْمِي مَنْ وَصَلَهَا وَصَلْتُهُ وَمَنْ قَطَعَهَا بَتَتُّهُ " .
sunnah.com