The Battle of Badr took place on this date, 17th of Ramaḍān – the day where Allāh ﷻ sent down the hosts of Jannah to assist the Muslims.
No other battle can be equated with the Battle of Badr. This is why Allāh ﷻ refers to this day as the day of Furqān – the differentiation factor between truth and falsehood.
It was also the month of the Furqān (another name for the Qur’ān). Allāh exposed the distinction between truth and falsehood, between guidance and deviation.
In the same month, Allāh ﷻ prescribed fasting so that Allāh may distinguish His sincere and committed slaves – who would bear the severity of hunger pangs from dawn till dusk in the most scorching of days in summer – against the faithless devotees who are slaves to their stomachs and jaws.
In short, this is a month of distinction in which from myriad angles, the sincere are set apart from the insincere.