The Cow - 2:185
Ramadan is the month in which the Qur´an was sent down, a guidance for mankind, a clear teaching and a book of law. Whoever reaches that month, let him fast. And those of you who are sick or traveling, fast on the other days for the number of days that you cannot fast. Allah desires ease for you and not hardship. So that you may complete the number (of fasting days) and glorify and give thanks to Allah Who has guided you to the truth.
Allah will reward those who thank Him and strive in His way with Paradise:
The Man/76:20
Wherever you look you will see blessings and a great government.
The Man/76:21
On them are garments of green velvet and silks. They are wearing silver bracelets. Their Lord will make them drink a pure drink.
The Man/76:22
This is your reward and your zeal has been thanked.
The Family Of Imran/3:195
"Their Lord answered them: "I will not leave unrewarded any of you who works, whether male or female; you are all equal. Those who emigrated, those who were expelled from their homes, those who were tortured and insulted in My way, those who fought and were killed... I will cover their evil deeds and place them in gardens with rivers flowing in them as a reward from Allah. The best reward is with Allah."
The Manifestation of Losses/64:17
And if you offer Allah a good loan, He will multiply it for you and forgive you. Allah is the Recompenser, the Compassionate.
The Women/4:147
Why should Allah punish you if you give thanks and believe? Allah is the Recompenser, the Mighty.
Council/42:23
"This is how Allah gives glad tidings to His servants who believe and act righteously. Say, "I do not ask of you any wage except the love of kinship."Whoever does a good deed, We increase his good deed. Allah is the Forgiving, the Appreciative."