Hadith 20506

وَقَالَ أَبُو بَكْرَةَ : قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ : " مَنْ قَتَلَ نَفْسًا مُعَاهَدَةً بِغَيْرِ حَقِّهَا ، لَمْ يَجِدْ رَائِحَةَ الْجَنَّةِ ، وَإِنَّ رِيحَهَا لَيُوجَدُ مِنْ مَسِيرَةِ خَمْسِ مِائَةِ عَامٍ " .
It is narrated from Hazrat Abu Bakrah (may Allah be pleased with him) that the Prophet (peace and blessings be upon him) said: The fragrance of Paradise can be perceived from a distance of five hundred years. Whoever kills a Mu'ahid (a non-Muslim under Muslim protection) unjustly, Allah makes the fragrance of Paradise forbidden for him.
Hadith Reference مسند احمد / أول مسند البصريين / 20506
Hadith Grading حکم دارالسلام: حديث صحيح، وهذا إسناد ضعيف لضعف على بن زيد