Sunan Ibn Majah, Volume 5, Book 37, Hadith 4172 (DarusSalam) ⓘ

It was narrated from Abu Hurairah that the Messenger of Allah said: “The likeness of the one who sits and listen to wisdom then only speaks of the bad things that he had heard, is that of a man who comes to a shepherd and says: “O shepherd, give me one of your sheep to slaughter,” and (the shepherd) says: “Go and grab the ear of the best of them.” Then he goes and grabs the ear of the sheepdog.’”

حَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ، حَدَّثَنَا الْحَسَنُ بْنُ مُوسَى، عَنْ حَمَّادِ بْنِ سَلَمَةَ، عَنْ عَلِيِّ بْنِ زَيْدٍ، عَنْ أَوْسِ بْنِ خَالِدٍ، عَنْ أَبِي هُرَيْرَةَ، قَالَ قَالَ رَسُولُ اللَّهِ ـ صلى الله عليه وسلم ـ ‏ "‏ مَثَلُ الَّذِي يَجْلِسُ يَسْمَعُ الْحِكْمَةَ ثُمَّ لاَ يُحَدِّثُ عَنْ صَاحِبِهِ إِلاَّ بِشَرِّ مَا يَسْمَعُ كَمَثَلِ رَجُلٍ أَتَى رَاعِيًا فَقَالَ يَا رَاعِي أَجْزِرْنِي شَاةً مِنْ غَنَمِكَ ‏.‏ قَالَ اذْهَبْ فَخُذْ بِأُذُنِ خَيْرِهَا ‏.‏ فَذَهَبَ فَأَخَذَ بِأُذُنِ كَلْبِ الْغَنَمِ ‏" ‏ ‏.‏