Reference: Fataawa al-Lajnah ad-Daa.imah lil-Buhooth al-‘Ilmiyyah wal-Iftaa. – Volume 11, Page 10, Fatwa No.4624
Question: What is the correct opinion concerning the Hijree year in which the Hajj began (was legislated)?
Response: The scholars have differed as to which year the Hajj was obligated. So, it is said in the fifth year, and it is said in the sixth year, and it is said in the ninth year and it is said in the tenth year. And the closest to that which is correct are the last two opinions and that it was either obligated in the ninth year or the tenth year.
And with Allaah lies all the success, and may Allaah send prayers and salutations upon our Prophet Muhammad ﷺ and his family and his companions.