It is narrated from a Companion (may Allah be pleased with him) that the Noble Prophet (peace and blessings be upon him) said one day: "Today your brother (the King of Abyssinia, Najashi) has passed away. Come, form rows and offer his funeral prayer."
Hadith Referenceمسند احمد / مسند الأنصار رضي الله عنهم / 23195
Hadith Gradingحکم دارالسلام:صحيح لغيره، وهذا إسناد ضعيف لضعف حمران بن أعين