القثاء بالرطب
A reported food pairing — fresh cucumber eaten together with fresh dates — noted by commentators as balancing a cooling food against a warming one.
رَأَيْتُ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ يَأْكُلُ الْقِثَّاءَ بِالرُّطَبِ
“I saw the Messenger of Allah ﷺ eating fresh cucumber together with fresh dates.” (meaning, not a literal translation)
This report comes from 'Abdullah ibn Ja'far, describing a directly observed eating habit rather than an explicit instruction — one of several hadith in this genre that record what the Prophet ﷺ was seen doing, which commentators then interpret for its dietary logic rather than treating as a command in itself.
Ibn al-Qayyim explains the pairing within humoral theory: cucumber's cooling, moistening nature is thought to offset the date's warming sweetness, easing digestion of both. This pairing principle — combining a cooling food with a warming one — appears repeatedly across his broader dietary discussions in Zad al-Ma'ad as a general approach to balancing a meal, not unique to this specific combination.
Modern nutrition doesn't use the classical hot/cold humoral framework, but the practical combination — a high-water, low-calorie vegetable with a naturally sweet, energy-dense fruit — is a nutritionally sensible pairing by contemporary standards too, for largely different reasons (fiber, hydration, and blood sugar response) than the ones the classical text describes.