It is narrated from Ibn Abbas (may Allah be pleased with them) that he said: The one performing Umrah will recite the Talbiyah until he begins the Tawaf, whether he starts it on foot or without walking (while riding).
Hadith Referenceمسند الإمام الشافعي / كتاب الحج / 831
Hadith Takhrijاسناده صحیح اخرجه البيهقي في المعرفة السنن والآثار (2945)۔