Hadithcore
Riyad as-Salihin, 1264

Ibn 'Abbas (May Allah be pleased with them) reported:

It was the practice of the Messenger of Allah (ﷺ) to not to omit fast on 'bright days' whether he was staying at a place or on a journey. <b>[An-Nasa'i]</b>.

وعن ابن عباس، رضي الله عنهما، قال‏:‏ كان رسول الله صلى الله عليه وسلم ‏

‏لا يفطر أيام البيض في حضر ولا سفر‏

‏ ‏(‏‏(‏رواه النسائي بإسناد حسن‏)‏‏)‏‏.‏

References1 variant
In-Book Reference
Book 8, Hadith 274
Sharh · explanationclick to expand
<b>Guidance from the Hadiths:</b><br> 1) Fasting three days every month is equivalent to fasting the whole year, for a good deed is rewarded by ten times as much.<br> 2) Fasting the three days in the middle of the month - 13, 14, and 15 - is the best form of fasting, for this was the more frequent practice of the Prophet (may Allah’s peace and blessings be upon him).<br> 3) They show the merit of the Companions, as they were keen to act upon the Prophet’s instructions throughout their lives.