Muhammad bin al-Munkadir narrates from his father, Sayyiduna al-Munkadir (may Allah be pleased with him), that the Messenger of Allah (peace and blessings be upon him) said: "Whoever performs tawaf around the House (the Ka'bah) seven circuits and does not engage in idle talk during it, it is as though he has freed a slave."
Hadith Referenceالمعجم الكبير للطبراني / باب الميم / 17970