The Prophet (SAS) began to receive revelations in Ramadan. Allah the Almighty says:

﴾ The month of Ramadhan in which was revealed the Qur'an, a guidance for the people and clear proofs of guidance and criterion (between the right and wrong) ... ﴿ (Al-Baqarah: 185)

﴾ Verily! We have sent it (this Quran) down in the night of Al-Qadr (Decree). And what will make know what the night Of Al-Oadr is? The night of Al-Qadr is better than a thousand months (i.e. worshipping Allah in that night is better worshipping Him a thousand months, i.e. 83 years 4 months). Therein descend the angels and the Ruh [ Jibril (Gabriel) ] by Allah's Permission with all Decrees. Peace! (All hat night. there IS Peace and Goodness from Allah to His believing slaves) until the appearance of dawn. ﴿ (Al-Qadr: 1-5)

﴾ Ha'. Mim. By the Clear Book. We revealed it on a Blessed Night, for We were intent on warning; (We revealed it on the Night) wherein every matter is wisely determined, by Our command. Verily, We were set to send a Messenger ﴿ (Al-Dukhan: 1-5)

﴾ ... if you have believed in Allah and in that which We sent down to Our Servant on the day of criterion (between right and wrong) - the day when the two armies met (at Badr).﴿ (Al-Anfal: 41)

This refers to the confrontation between the Prophet (pbuh) and the polytheists in the battle or Badr.