عَنْ عَائِشَةَ قَالَتْ: قَالَ النَّبِيُّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «إِنَّ أَطْيَبَ مَا أَكَلْتُمْ مِنْ كَسْبِكُمْ وَإِنَّ أَوْلَادَكُمْ مِنْ كَسْبِكُمْ» . رَوَاهُ التِّرْمِذِيُّ وَالنَّسَائِيُّ وَابْنُ مَاجَهْ. وَفِي رِوَايَةِ أَبِي دَاوُدَ وَالدَّارِمِيِّ: «إِنَّ أَطْيَبَ مَا أَكَلَ الرَّجُلُ مِنْ كَسْبِهِ وَإِنَّ وَلَده من كَسبه»
Translation
Abu Umama reported God’s Messenger as saying

"Do not sell, buy or teach singing-girls, and the price paid for them is unlawful. To similar effect has been sent down, 'Among men are those who purchase frivolous talk' (Al-Qur'an 31:6).Ahmad, Tirmidhi and Ibn Majah transmitted it, Tirmidhi saying that this is a gharib tradition and that ‘Ali b. Yazid the transmitter is declared to be a weak traditionist.