بسم الله الرحمن الرحيم
(1) The Islamic Shariah is based on four foundations: (1) The Holy Quran. (2) Hadith. (3) Ijma (consensus). (4) Qiyas (analogy). It is necessary and wajib to follow these sources. Ijma and Qiyas have been extracted from the holy Quran and Hadith. These four are the Usool (principle) of Shariah. It is foolish to raise questions of why and how in Usool. You cannot ask any judge about the law of Indian court why it is so.
(2) As it is necessary for us to follow the holy Quran and Hadith, in the same way it is necessary to follow those Usool and Furoo (derivative issues) extracted from the holy Quran. Otherwise people will start following their own will in the name of the Quran and Hadith. It is obvious that the person who follows his own will shall not be called the follower of the holy Quran and Hadith.
(3) It is meanness to bring gold and money for a husband from the home of bride. You should avoid participating in such walimah.
Allah knows Best!
Darul Uloom Deoband