Fiqh-us-Sunnah Volume 1, Purification and Prayer, Fiqh 1.040.

Ibn ‘Abbas reported that the Messenger of Allah said, “Circumambulation is a type of prayer, but Allah has permitted speaking during it. Whoever speaks during it should only speak good.”

This hadith is related by at-Tirmizhi, ad-Daraqutni, al-Hakim, Ibn as-Sakin and Ibn Khuzaimah, who classified it as sahih.