عَنْ سَهْلِ بْنِ سَعْدٍ رَضِيَ اللَّهُ عَنْهُ قَالَ سَمِعْتُ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ يَقُولُ لَا تَسُبُّوا تُبَّعًا فَإِنَّهُ قَدْ كَانَ أَسْلَمَ
It is narrated from Sayyiduna Sahl bin Sa’d (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: Do not speak ill of Tubba’, because he had become a Muslim.