Dear respected Shaykh, assalamu alaikum wa rahmatullahi wa barakatuh. I fast the first ten days of Thul Hijjah. I am afraid of doing something that is not from the guidance of the Prophet (peace be upon him). However, I fast these days because I want to increase my good deeds. Is this permissible? أنا يا شيخ أصوم العشرة الأولى كلها فهل هذا جائز لأنني أخاف أن أفعل شيئا ليس من هدي الرسول - صلى الله عليه وسلم- ولكنني أصومها من اجل الزيادة في الأعمال الصالحة فهل هذا جائز؟

Praise be to Allah, and may Allah’s peace and blessings be upon the Messenger of Allah, his family and his companions. Wa alaikum assalam wa rahmatullahi wa barakatuh. As to what follows: In response to your question, we say:   Fasting on  ‘Eid (the tenth of Thul Hijjah) is not permissible because the Prophet (peace be upon him) forbade that. The Prophet (peace be upon him) recommended fasting on the ninth of Thul Hijjah as was stated in Sahih Muslim in the hadith of Abu Qatadah that the Prophet (peace be upon him) said, “I seek from Allah that fasting on the day of 'Arafah may atone for the sins of the preceding and the coming years” [Muslim (1162)]. The majority of the scholars are of the opinion that fasting for the first nine days of Thul Hijjah is permissible because it falls under the generality of the hadith of the Prophet (peace be upon him) where he stated, “There are no days during which the righteous action is so pleasing to Allah than these days (i.e., the first ten days of Dhul-Hijjah)." He was asked: "O Messenger of Allah, not even Jihad in the Cause of Allah?" He (peace be upon him) replied, "Not even Jihad in the Cause of Allah, except in case one goes forth with his life and his property and does not return with either of it," and fasting is a righteous action according to the consensus of the scholar.