Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) relates that Musa bin Imran (peace be upon him) performed Hajj among fifty thousand men of the Children of Israel, wearing two Qatawani cloaks, and he was reciting the talbiyah: 'Labbayk Allahumma labbayk, labbayk ta'abbudan wa riqqan, labbayk ana 'abduka ana ladayka ladayka ya kashshaf al-kurab' (Here I am, O Allah, here I am; here I am in worship and servitude; here I am, I am Your servant, I am before You, before You, O Remover of distresses). And the mountains answered him.
Imam al-Shafi'i (may Allah have mercy on him) said: It has not been related to us about any prophet or any of the past nations that anyone ever came to the House except in the state of ihram, and whenever the Messenger of Allah (peace and blessings be upon him) entered Makkah he entered in the state of ihram, except on the occasion of the Conquest of Makkah.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الحج / 9838