question #1 Sahih al-Bukhari 1657, Book 25, Hadith 138 : What is the significance of performing two rak’at prayers during Hajj at Mina?

I offered (only a) two rak`at prayer with the Prophet (at Mina), and similarly with Abu Bakr and with
`Umar, and then you d offered in opinions. Wish that I would be lucky enough to have two of the four
rak`at accepted (by Allah).