Sunan an-Nasa'i, Book 48, Hadith 242 (In-Book) ⓘ
It was narrated that Anas said: "The Messenger of Allah [SAW] said: 'We have had a ring made with an inscription, and no one else should copy this inscription.'"
أَخْبَرَنَا إِسْحَاقُ بْنُ إِبْرَاهِيمَ، وَعَلِيُّ بْنُ حُجْرٍ، - وَاللَّفْظُ لَهُ - قَالاَ حَدَّثَنَا إِسْمَاعِيلُ، عَنْ عَبْدِ الْعَزِيزِ بْنِ صُهَيْبٍ، عَنْ أَنَسٍ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " قَدِ اصْطَنَعْنَا خَاتَمًا وَنَقَشْنَا عَلَيْهِ نَقْشًا فَلاَ يَنْقُشْ عَلَيْهِ أَحَدٌ " .
also referenced under: Hadith 5281 (Reference) & Volume 6, Book 48, Hadith 5283 (DarusSalam)