Is it necessary to pay zakat on the money that is saved throughout the year from salary, knowing that the savings increase and decrease according to expenses, and the amount has completed a year and reached the nisab?

Is it permissible to combine the Zakat of money that has not reached the Nisab with the Zakat of gold that has reached the Nisab, or should we pay the Zakat of each type separately?

Regarding tayammum, you mentioned a criterion for what can be used for it, which is that it should not burn or soften. You provided examples of trees and minerals, but even stones and rocks can burn and soften, as evidenced by volcanic lava when exposed to high temperatures, and shale oil can be released if the heat is intense enough, causing it to soften and become like volcanic lava. Is there any clarification on this?

A lady had a certain amount of gold stolen from her, and after years, the thief returned money to her instead of the gold, and the amount of money reaches the nisab. Does she have to pay zakat on it?

A person has saved an amount of money to buy a house, and a lunar year has passed, and he has paid zakat on it. Should he pay zakat on it once or every year?

I have olive oil, and I am in debt, is Zakat obligatory on me?

A woman suffers from asthma, and her doctor has required her to refrain from bathing for extended periods and under certain conditions. Is it permissible for her to perform tayammum after sexual relations, especially since her husband does not take her health condition into consideration?

I have an amount that I inherited from my father and used it in trade, and I take its profit to help me in life, especially since my husband is sick and does not work. This capital remains as it is. Is there Zakat due on it, or was I obligated to pay Zakat on it before I started using it? If there is Zakat due, what is its amount?

You said that wiping the hands in tayammum is done by wiping the hands up to the elbows, but the correct method is to the wrists. Is there a difference in the method of tayammum among the imams?