Ibn Majah

Benefits and Issues:
(1)
Horses that are used for work and slaves that are kept for service are not obligatory upon one to pay zakat on them. However, if a person is engaged in the business of buying and selling horses or slaves, then he should estimate their value and pay zakat on them just like other trade goods. There are multiple narrations regarding this, but there is some discussion about their chains of transmission. Nevertheless, it can be said that these ahadith, when taken together, can be used as evidence.
Umar ibn Abd al-Aziz radi Allahu anhu also issued orders to collect zakat from traders on their trade goods. (Muwatta Imam Malik, Chapter: Zakat on Trade Goods: 1/235)
Its chain is hasan (good).
Imam Bayhaqi rahimahullah, giving preference to the obligation of zakat on trade goods, has stated:
(This is the view of the majority of the scholars) (Sunan al-Bayhaqi: 4/147)
“The majority of the scholars hold this view.”

(2)
A dirham was a silver coin, whose weight according to current calculation is 2.975 grams, and according to some, 3.06 grams.
Zakat becomes obligatory when there is at least two hundred dirhams of silver.
The Prophetic instruction is:
“There is no zakat on less than five awqiyah.” (Sahih al-Bukhari, Zakat, Chapter: Zakat on Silver, Hadith: 1447)
An awqiyah is forty dirhams. (Jami‘ al-Tirmidhi, Zakat, Chapter: What Has Been Reported Regarding the Charity of Crops, Fruits, and Grains, Hadith: 627)
Most scholars have stated that the amount of two hundred dirhams is equivalent to fifty-two and a half tola (a traditional unit of weight).

(3)
The nisab (minimum threshold) for gold is twenty dinars, which amounts to seven and a half tola.
According to current standards, its weight is 85 grams.

(4)
The amount of zakat on gold and silver is one-fortieth, for example:
If someone possesses ten tola of gold, then it is obligatory for him to pay zakat equivalent to a quarter tola (three masha, i.e., 2.916 grams) of gold.

(5)
The nisab for cash is equivalent to that of gold, because according to the current system, currency notes are considered as substitutes for gold. Therefore, in international trade, countries pay and receive gold from each other. However, the majority of scholars have based the zakat of cash on the nisab of silver, i.e., at least the amount equivalent to fifty-two and a half tola of silver. Whoever has surplus cash equal to this amount and a year passes over it, he should pay zakat at the rate of two and a half percent.
The reason, according to them, is that this nisab benefits the poor and needy more, because in this way, more people will reach the nisab and more zakat will be collected.
And Allah knows best what is correct.