As salaam alaikum va rahamatullahi va barkatahu

I would like to know, based on the Qur’an and authentic Hadith, who is responsible for the financial expenses of Nikah and Walima—the bride ( Girl/Woman) or the groom’s (Boy/Man) family?

Additionally, is there any requirement in Islam to arrange separate gatherings with food for Nikah and food for Walima ?

Furthermore, many marriages today involve excessive spending, lavish functions, and financial burden on families. What does Islam say about such wasteful expenditure in weddings?

Kindly provide guidance with references from the Qur’an and authentic Hadith.