Sayyiduna Abu Huraira (may Allah be pleased with him) said that the Messenger of Allah (peace and blessings be upon him) said: "Do not fast a day or two before Ramadan, except for a person who has the habit of fasting on those days, then he may fast on that day as well."
Hadith Takhrijاس حدیث کی سند صحیح اور تخریج پیچھے گذر چکی ہے۔ نیز دیکھئے: [بخاري 1914] ، [مسلم 1082] ، [أبوداؤد 2335] ، [ترمذي 684]
Brief Explanation
(Commentary on Hadith 1726)
The meaning of this hadith is that if a person habitually fasts every week on Monday or Thursday, and coincidentally that day falls in the last dates of Sha'ban, then he may observe that fast. The hadith specifically establishes the prohibition and dislike (karahah) of fasting one or two days before Ramadan solely in anticipation of or out of respect for Ramadan.