question #1 Sahih al-Bukhari 2394, Book 43, Hadith 10 : What is the significance of performing two rak’ahs upon entering a mosque?

I went to the Prophet (ﷺ) while he was in the Mosque. (Mas`ar thinks, that Jabir went in the forenoon.)
After the Prophet (ﷺ) told me to pray two rak`at, he repaid me the debt he owed me and gave me an extra
amount.