(a) Abdullah bin Umar (may Allah be pleased with him) says that when the she-camel of the Messenger of Allah (peace and blessings be upon him) stood up with him near the mosque of Dhul-Hulayfah, he (peace and blessings be upon him) recited this talbiyah: 'Labbayk Allahumma labbayk, labbayk la sharika laka labbayk, inna al-hamda wa al-ni'mata laka wa al-mulk, la sharika lak' (Here I am, O Allah, here I am; here I am, You have no partner, here I am. Indeed, all praise and blessing are Yours, and the dominion; You have no partner). And Abdullah (may Allah be pleased with him) used to say: This is the talbiyah of the Messenger of Allah (peace and blessings be upon him).
(b) Abdullah bin Umar (may Allah be pleased with him) used to add these words along with it: 'Labbayk wa sa'dayk, wa al-khayru bi-yadayk, labbayk wa al-raghba'u ilayka wa al-'amal' (Here I am, and at Your service for my good fortune; all good is in Your two hands; here I am, and all longing and deeds are directed to You).
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الحج / 9027