Isru Chag: The Kedushas Levi and Chasam Sofer Reveal the Unique Status of the Day

What is the origin of the concept of Isru Chag? What does the verse in Tehillim (in Hallel) mean when it says “אסרו חג בעבותים עד קרנות המזבח”, how do we “tie ourselves” to Yom Tov?

Shiur provided courtesy of Torah Anytime