It is narrated from Sayyiduna Ibn Abbas (may Allah be pleased with them both) that the Messenger of Allah (peace and blessings be upon him) said: "Circumambulating (tawaf) the House of Allah is just like prayer, except that Allah Almighty has permitted speaking during it; so whoever speaks, let him say nothing but good."
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 10909