Sunan Abi Dawud 1776

Ibn `Abbas said:Duba`ah, daughter of al-Zubair bin `Abd al-Muttalib, came to the Messenger of Allah(SWAS) and said Messenger of Allah (SWAS) I want to perform Hajj; may I make a provision? He said Yes. She asked how should I say? He replied : Say “ Labbaik Allahumma Labbaik (I am at Thy service, Oh Allah, I am at Thy service). The place where I took off Ihram will be where Thou restrainest me.”