بُلُوغُ الْمَرَامِ
Bulugh al-Maram 617
The Book of Zakah
وَلِلدَّارَقُطْنِيِّ, عَنْ مُعَاذٍ: { فَأَمَّا اَلْقِثَّاءُ, وَالْبِطِّيخُ, وَالرُّمَّانُ, وَالْقَصَبُ, فَقَدْ عَفَا عَنْهُ رَسُولُ اَللَّهِ - صلى الله عليه وسلم -} وَإِسْنَادُهُ ضَعِيف ٌ [1] .
Imam Ad-Daraqutni related on the authority of Mu’adh (RAA), ‘As for cucumbers, watermelons, pomegranates, and sugar-cane, the Messenger of Allah (ﷺ) has exempted them from Zakah.’ It is transmitted with a weak chain of narrators.
Sunnah.com reference: Book 4, Hadith 19