This excerpt is taken from Sheikh Farooq Rafi Sahib's book Qurbani, Aqiqah, and Ashra Zil-Hijjah.
The first ten days of Dhu al-Hijjah are important also because the tenth day of Dhu al-Hijjah is superior and more exalted than all other days of the year. It is narrated from Sayyiduna Abdullah ibn Qurt رضي الله عنه that the Messenger of Allah صلی اللہ علیہ وسلم said:
إن أعظم الأيام عند الله يوم النحر ثم يوم القر وهو الذى يليه
“The greatest day in the sight of Allah is the Day of Sacrifice (the tenth of Dhu al-Hijjah), then the day after the tenth (the eleventh of Dhu al-Hijjah).”
Reference: Sahih: Sunan Abi Dawood: 1765. Musnad Ahmad: 350/4. Sahih Ibn Khuzaymah: 2917. Mustadrak Hakim: 221/4.
This hadith is evidence that the Day of Sacrifice is the best day of the year, and Imam Ibn Taymiyyah رحمه الله also confirmed this.
Question: Among the Day of Arafah, Friday, Eid al-Fitr, and the Day of Sacrifice, which day is superior?
Answer: The scholars agree on this issue that among the days of the week, Friday is the best day, and among all the days of the year, the Day of Sacrifice (the tenth of Dhu al-Hijjah) is the best. However, some scholars have also considered the Day of Arafah to be superior, but the first view is stronger because the Prophet صلی اللہ علیہ وسلم narrated the virtue that “The best day in the sight of Allah among all days is the Day of Sacrifice (the tenth of Dhu al-Hijjah), then the eleventh of Dhu al-Hijjah.”
Also, this day holds virtue because it includes the standing at Muzdalifah, the stoning of the Jamrah Aqabah, the sacrifice, shaving or trimming the hair, and the Tawaf al-Ifadah—great acts of worship—and by consensus of the scholars, these are the best acts of worship performed in this blessed day throughout the year.
Reference: Fatawa Ibn Taymiyyah: 288/25.