Reb Velvel and his nephew Reb Yosef Dov have a wide ranging debate over when the mitzvah of Ketoret (incense in the Temple) is fulfilled and the nature of the Kohen Gadol entering the Holy of Holies on Yom Kippur

Reb Velvel explains how the concept of Mehadrin (beautifying a Mitzvah) applies to lighting the Chanukah candles

Reb Velvel analyzes two different types of Hallel, and specifically the nature of Hallel at the Seder night

Reb Velvel analyzes the status of a Megillah in halacha and whether it requires sanctity to be used in Purim 

Reb Velvel explains why a Megillah requires lines etched in the parchment

Reb Velvel defines the nature of the afternoon before Tisha Ba'av and how that leads into the mourning of Tisha Ba'av. 

Reb Velvel defines the essence of Tisha Ba'av (which the Chasam Sofer disagrees with). 

Reb Velvel explains two fundamental approaches to why the court would add a month to create a leap year 

Reb Velvel explains two approaches to the issue of whether a Succah needs to be comfortable to dwell in 

Reb Velvel develops two components to the mitzvah to drink four cups at the Seder