Narrated `Abdullah:

Allah Apostle said in Hajjat-al-Wada`, "Which month (of the year) do you think is most sacred?" The people said, "This current month of ours (the month of Dhull-Hijja)." He said, "Which town (country) do you think is the most sacred?" They said, "This city of ours (Mecca)." He said, "Which day do you think is the most sacred?" The people said, "This day of ours." He then said, "Allah, the Blessed, the Supreme, has made your blood, your property and your honor as sacred as this day of yours in this town of yours, in this month of yours (and such protection cannot be slighted) except rightfully." He then said thrice, "Have I conveyed Allah's Message (to you)?" The people answered him each time saying, 'Yes." The Prophet (ﷺ) added, 'May Allah be merciful to you (or, woe on you)! Do not revert to disbelief after me by cutting the necks of each other.'