Purification

Scholars of Islam, As-Salamu `Alaykum wa Rahamtu Allah wa Barakatuh. May Allah accept your efforts in explaining the truth for people! I have a question that I would like you to clarify. I use the modern toothbrush instead of the traditional siwak; is it ok? Moreover, what is the virtue of using Siwak in Islam?

Asalamu Alaikom,I have a question regarding a waterproof sun protection product.I have read that once something waterproof is applied to the skin, wudu will be void because water does not get to the skin.My problem now is, when I go to swim, I have to apply sun protection product, wich is waterproof, thus my wudu would be invalid.Could you tell me what to do in this situation

assalam allaikum w r w b. this website is offering a guidance to ummah.sir i am 34 year doctor . my scalp hairs are almost gray and beard also started to be graying. last few years i was using natural henaa. sir can i color my hairs with artificial dye? can i color beard too? is black color allowed ? Is  it going to affect wudu ,gusl ,prayer or ibadat ? please guide me .zajak ALLAH.