صحيح البخاري

Narrated Warrad:

(the clerk of Al-Mughira bin Shu`ba) Muawiya wrote to Al-Mughira: "Write to me a narration you have heard from Allah's Messenger." So Al-Mughira wrote to him, "I heard him saying the following after each prayer: 'La ilaha illal-lahu wahdahu la sharika lahu, lahu-l-mulk wa lahuI-hamd, wa huwa 'ala kulli Shai-in qadir.' He also used to forbid idle talk, asking too many questions (in religion), wasting money, preventing what should be given, and asking others for something (except in great need), being undutiful to mothers, and burying one's little daughters (alive).