It is narrated from Sayyiduna Abu al-Fil (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "Do not speak ill of him" - meaning Ma'iz bin Malik (may Allah be pleased with him).
Hadith Referenceالمعجم الكبير للطبراني / مسند من يعرف بالكنى / 19020