Hadith 2429
Narrated Abu Hurairah: The Messenger of Allah ﷺ as saying: The most excellent fast after Ramadan is Allah's month al-Muharram, and the most excellent prayer after the prescribed prayer is the prayer during night.
Hadith 2430
Narrated Uthman bin Hakim: I asked Saeed bin Jubair about fasting during Rajab. He said: Ibn Abbas told me that the Messenger of Allah ﷺ used to fast to such an extent that we thought that he would never break his fast ; and he would go without fasting to such and extent that he would never fast.