Allah Ta’ala has selected Ramadhan for the revelation of His Word, the Holy Quran. He has also shown His preference for this month over other months by mentioning its name in the Holy Quran.
The month of Ramadan in which was revealed the Qur'an, a guidance for mankind, and clear proofs of the guidance, and the Criterion (of right and wrong). Surah Al Baqarah (2:185)
With the coming of the month of Ramadhan, Allah Ta’ala floods the world with His Mercy. The doors of the sky are opened. The doors of Jannah are opened. Everywhere, there is an expression of His Mercy. One of the blessed attributes of the Holy Prophet (Sallallahu alaihi wa sallam) is His generosity and benevolence. In the month of Ramadhan, the Holy Prophet (Sallallahu alaihi wa sallam) became even more generous. There is a Hadith in Sahih Bukhari:
Translation: It has been narrated on the authority of Hadhrat Abdullah bin Abbas (May Allah be well pleased with him) that the Holy Prophet (Sallallahu alaihi wa sallam) was the most generous of all and His generosity would be at its highest point in the month of Ramadhan, when Jibrail (peace be upon him) would come to His presence. (Sahih Bukhari, Vol 1, Pg No: 3)
Imam Baihaqi has recorded a Hadith in his Shu'ab Ul Iman:
Translation: It has been narrated on the authority of Hadhrat Abdullah bin Abbas (May Allah be well pleased with him), he said: When the month of Ramadhan came, the Holy Prophet (Sallallahu alaihi wa sallam) released every prisoner and would give to everyone who asked. (Baihaqui, Shu’ab Ul Iman, Hadith No: 3475))
Allah Ta’ala has given absolute authority to the Holy Prophet (Sallallahu alaihi wa sallam) to decide the rules and the reward for following them. Since He (Sallallahu alaihi wa sallam) is all the more generous in Ramadhan, as per His habit, He (Sallallahu alaihi wa sallam) decreed special rules for Ramadhan and gave glad tidings of special reward in this month.
The reward of an optional (Nafl) is equal to that of an obligation (Fardh), the reward of a Fardh is increased seventy-fold; the reward for providing means to a fasting person to break the fast is a drink from the Houz e Kouthar; the promise to increase a Momin's sustenance (Rizq); the one in itikaaf is rewarded for every virtuous act etc.
The special reward for these virtuous acts of Ramadhan has been mentioned in the Hadith only. No verse of the Holy Quran mentions this. This is only the generosity of the Holy Prophet (Sallallahu alaihi wa sallam) and the result of His benevolence. A special virtuous act in Ramadhan is Taraweeh.