Mujahid (may Allah have mercy on him) narrated that we were in the company of Sayyiduna Abdullah bin Abbas (may Allah be pleased with him). People mentioned the Dajjal and said that the Prophet (peace and blessings of Allah be upon him) has said that "Kafir" will be written between his two eyes. So Sayyiduna Ibn Abbas (may Allah be pleased with them both) said: I did not hear this, but yes, he (the Prophet) said: It is as if I am seeing Musa (peace be upon him), when he descended into the valley, he was saying "Labbaik."
Hadith Referenceاللؤلؤ والمرجان / كتاب الايمان / 105
Hadith Gradingمحدثین:«صحیح»
Hadith Takhrij«صحیح، أخرجه البخاري في: 25 كتاب الحج: 30 باب التلبية إذا انحدر في الوادي»