Not graded
Mishkat al-Masabih 2826
Narrator:Abu Hurayrah
وَعَنْ أَبِي هُرَيْرَةَ قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «الرِّبَا سَبْعُونَ جُزْءًا أيسرها أَن الرجل أمه»
Abu Huraira reported God’s Messenger as saying, "Usury has seventy parts, the least important being that a man should marry his mother.” Ibn Majah and Baihaqi, in Shu'ab al-iman
Cited in Mishkat al-Masabih (No. 2826).