The Prophet said: "Fasting during the winter is an easy reward."
Jami` at-Tirmidhi Book 8, Hadith 116
← Previous Hadith "The Messenger of Allah would struggle (to perform Salat more) during the last ten (nights) more than he would struggle in the rest of it."

Jami` at-Tirmidhi Book 8, Hadith 115 Next Hadith → "When the following was revealed: 'And for those upon whom it is difficult, (they may) feed a poor person' - if one of us wanted we would not fast, and pay the ransom, until the Ayah after it was revealed abrogating it."

Jami` at-Tirmidhi Book 8, Hadith 117