Hadith: O Messenger of Allah, which bliss will we be asked about; there are only two black things available: dates and water? He said: This will certainly come

عن الزبير بن العوام قال: لما نزلت: {ثم لتسألن يومئذ عن النعيم} قال الزبير: يا رسول الله، وأي النعيم نسأل عنه، وإنما هما الأسودان التمر والماء؟ قال: أما إنه سيكون.
[حسن] - [رواه الترمذي وابن ماجه]

Az-Zubayr ibn al-‘Awwām (may Allah be pleased with him) reported: When {Then on that Day you will surely be asked about your worldly bliss} was revealed, Az-Zubayr said: "O Messenger of Allah, which bliss will we be asked about; there are only two black things available: dates and water?" He said: "This will certainly come."
Hasan/Sound. - [At-Tirmidhi]

Explanation

When the verse {Then on that Day you will surely be asked about your worldly bliss} [Surat at-Takāthur: 8] was revealed - means: you will be asked about the duty of showing gratitude for the favors that Allah has bestowed upon you - Az-Zubayr ibn al-‘Awwām (may Allah be pleased with him) said: O Messenger of Allah, what bliss will be questioned about? We only have two blessings that do not require questioning us, given their low value. These are the two black things: dates and water. Dates of Madīnah are mostly black. As for water, it was added in this description because the Arabs used to combine coupled things and call them by the same name. Thereupon, the Prophet (may Allah’s peace and blessings be upon him) said: This will certainly come. This has two probable meanings: First: The bliss you will be asked about will certainly come to you. Second: The question regarding your current condition will certainly come, for these two are among the great blessings bestowed by the Almighty Lord.