What is the reason for the difference between Al-Bukhari's Hadith (645) and (646) regarding the virtue of congregational prayer over individual prayer, where one mentions twenty-seven degrees and the other twenty-five degrees?

The reconciliation between the two hadiths regarding congregational prayer — [the one stating] twenty-five degrees and [the one stating] twenty-seven degrees — is achieved through three aspects:

1. There is no contradiction between them, as mentioning a lesser amount does not negate a greater amount. 2. The Prophet initially informed [people] of the lesser amount, then Allah informed him of an increase in merit. 3. It varies according to the circumstances of the worshippers and the prayer. Some receive twenty-five and others twenty-seven, depending on the completeness and humility of their prayer.

Al-Hafiz Ibn Hajar holds the view that the twenty-seven degrees are for audible prayers, and the twenty-five degrees are for silent prayers.