Abdullah bin Umar reported,

The Messenger of Allah ﷺ said, "There are no days greater in the sight of Allah, nor in which deeds are more beloved to Allah, than these days," meaning the ten days. "So increase in them the saying of la ilaha illa Allah and al-hamdu lillah."

Azami 12789

Sahih

عن ابن عمر قال

قال رسول الله ﷺ: ما من أيام أعظم عند الله، ولا العمل فيهن أحب إلى الله من هذه الأيام، فأكثروا فيها من التهليل والتحميد يعني أيام العشر.

الأعظمي 12789صحيح
Contents
Reference
Commentary
Ayat
Collection
Jami al-Kamil
Book
Tafsir of the great Quran
Chapter
Tafsir of Surah Anbiya
Section
His saying, "That they may witness benefits for themselves and mention the name of Allah on known days over what He has provided for them of livestock. So eat of them and feed the miserable poor." And His saying, "And mention the name of Allah on known days," the known days are the ten days of Dhul-Hijjah. This was said by Ibn Abbas and others
Numbering
Jami al-Kamil 12789 (2nd edition)
Azami 12789