What lesson did the Prophet Muhammad (saw) teach us when he said, 'Learn the recitation of the Qur'an from (any of these) four persons: `Abdullah bin Masud, Salim the freed slave of Abu Hudhaifa, Ubai bin Ka`b, and Mu`adh bin Jabal' ?
 Narrated Masruq:                     `Abdullah (bin Mas`ud) was mentioned before `Abdullah bin `Amr. The latter said, "That is a man I continue to love because I heard Allah's Apostle saying, ' Learn the recitation of the Qur'an from (any of these) four persons: `Abdullah bin Masud, Salim the freed slave of Abu Hudhaifa, Ubai bin Ka`b, and Mu`adh bin Jabal." I do not remember whether he mentioned Ubai first or Mu`adh.