Bulugh al-Maram

Lexical Explanation:
«اَلزَّبِيبِ» Dried grapes (raisins).
«اَلْقِثَّاءُ» With a kasrah under the letter "qaf", «ثا» with shaddah on «مثلثه» and an alif mamdudah at the end, cucumber.
«اَلْبِطِّيخُ» With a kasrah under the letter "ba" and shaddah on "ta", watermelon.
«الْرُمَّانُ» With a dammah on the letter "ra" and shaddah on "mim", pomegranate.
«الْقَصَبُ» With a fathah on both "qaf" and "dad", sugarcane and every produce of the earth whose stem has joints and nodes, such as bamboo and reed, etc. This hadith restricts the obligation of zakat on grains and fruits to these four types. This is the opinion of one group.
And the opinion of other scholars is that every item that is equivalent to these four types, i.e., that can be stored and preserved, is also subject to zakat. They say that the restriction in this hadith is not a real (haqiqi) restriction but a relative (idafi) one, meaning that the Prophet (sallallahu alayhi wa sallam) mentioned them in accordance with the crops available in Yemen at that time, or he gave this ruling to exclude those vegetables in which zakat is not obligatory. Thus, crops like rice, maize, etc., which people generally store in most regions, are also subject to zakat. According to the researchers, this opinion is more reliable.

Benefit:
Our esteemed researcher has declared the narration of Abu Musa and Mu'adh ibn Jabal (radi Allahu anhuma) to be weak in its chain. However, Shaykh al-Albani (rahimahullah) has declared it authentic. See: [ارواء الغليل : 278 ، 3]
Furthermore, according to some scholars, it is mursal, and for this reason, most of the imams are of the opinion that in addition to the four mentioned items, every other produce of the earth is also subject to ‘ushr (one-tenth) or half ‘ushr, such as millet, maize, chickpeas, rice, mustard, gourd, and sugarcane, etc. Their evidence is the Qur’anic verse:
«وَمِمَّا اَخَرَجْنَا لَكُم مِّنَ اَلَارْضِ» [البقرة : 2 : 267]
and the generality of the hadith «فِيمَا سَقَتِ السَّمَاءُ». Both the Qur’an and hadith use general wording that zakat is due on every produce of the earth. This generality demands that ‘ushr or half ‘ushr be taken from all. The only things excluded from this generality are those for which there is an exception established by hadith, such as the exception of vegetables, which is established by hadith; therefore, there is no ‘ushr or half ‘ushr on them. However, from the exception of vegetables, it is indirectly established that any produce of the earth that can be preserved for a long time, ‘ushr or half ‘ushr should be paid on it. On this basis, the imams who uphold this generality have declared two conditions necessary for the produce of the earth: first, that it is measured by volume or weight; second, that it is stored as food. This position is supported by the hadith in Sahih Muslim in which the Prophet (sallallahu alayhi wa sallam) said: “There is no zakat on any grain or date until it reaches five wasq.” [صحيح مسلم ، الزكاة ، باب ليس فيما دون خمسة اوسق صدقة ، حديث : 979]
In this hadith, the word “hab” (grain) is general, which includes every type of grain, so it encompasses all kinds of produce that are eaten and stored. Similarly, among fruits, those that last until the next harvest are also considered under this principle and rule as produce from which zakat is taken, because the reason of storing as food is present in them as well. However, fruits that cannot last for long will be considered as vegetables, i.e., there will be no zakat on them. This is the preferred and correct position. Shaykh Safiur Rahman Mubarakpuri (rahimahullah) has also indicated towards this, and according to the researchers among the scholars, this opinion is more reliable. «والله اعلم» For further details, see: [فقه السنة الزكاة]
The narration of Mu’adh (radi Allahu anhu) which is referenced from Sunan al-Daraqutni is weak. The reason for its weakness is a weak narrator, and its chain is also disconnected, as the author has clarified in al-Talkhis, and our esteemed researcher has also declared it weak. See: Tahqiq wa Takhrij Hadith Haza.