Muawiya rarely narrated anything from the Prophet ﷺ. Yet he hardly ever let a Friday pass without relating these words from the Messenger of Allah ﷺ. He would say, "Whoever Allah wishes good for, He grants him understanding of the religion. This wealth is sweet and green. Whoever takes it by its rightful means will be blessed in it. Beware of mutual flattery, for it is slaughter."
كان معاوية، قلما يحدث عن النبي ﷺ قال: فكان قلما يكاد أن يدع يوم الجمعة هؤلاء الكلمات أن يحدث بهن عن رسول الله ﷺ يقول: من يرد الله به خيرا يفقهه في الدين، وإن هذا المال حلو خضر، فمن يأخذه بحقه يبارك له فيه، وإياكم والتمادح، فإنه الذبح.
Ahmad (16846) and Ibn Majah (3743) both narrated it through routes from Shubah, from Saad bin Ibrahim, from Mabad Juhani, and he related it. The wording is Ahmad's, and Ibn Majah abridged it. Its chain is hasan because of Mabad bin Khalid Juhani, for he is one whose hadith is hasan. Mabad Juhani was the first to publicly promote the doctrine of denying divine predestination in Basra, but there is nothing in this hadith of his that supports his heretical innovation.