The Messenger of Allah ﷺ said in his talbiyah, "Labbayk, God of Truth."
حدثنا وكيع حدثنا عبد العزيز بن عبد الله بن أبي سلمة عن عبد الله بن الفضل عن الأعرج
أن رسول الله ﷺ قال في تلبيته لبيك إله الحق
Its chain of transmission is sahih, it has already appeared at 8478, and it was also reported by Nasai (5/161, no. 2752), Ibn Majah (2/974, no. 2920), Abu Hanifa (122), and Hakim (1/449), who graded it sahih, and Dhahabi agreed with him.