Imam Ahmad recorded in his Musnad: Ibraaheem ibn Sa’d narrated to us from his father from ‘Abdullaah ibn Ja’far (radiallaahu ‘anhu), who said:
I saw the Prophet (salallaahu ‘alaihi wa sallam) eating cucumber with fresh dates.
(Musnad Ahmad, Vol. 1, p. 203. The Isnaad of this hadeeth is saheeh according to the conditions set by al-Bukhaaree and Muslim.)
Our beloved Prophet Muhammad (pbuh) combined cucumbers with ripe dates saying: “the heat of the latter is reduced by the coolness of the former.” (Bukhari, Muslim, Abu Dawood and Ibn Majah)