Hazrat Sahl bins Sa’ad R.A. reports that Rasulullah (Salallaho Alaihi Wassallam) said:
“when a Muslim shouts Labbaik, then verily every stone, tree and all the ground to his right and to his left recites the same, and this continues till that cry reaches the end of the earth”.
The recitation of the cry ‘Labbaik’ is the symbol and emblem of the Hajj. This is borne out by many Ahaadith. In Knaz we find a report that when Moosa A.S used to recite Labbaik, Allah used to reply: “Labbaik O Moosa: (Kanz). It is Allah’s mercy that not only the Hajji’s Labbaik, but his every action earns for him great reward.