Prayer during the night should consist of pairs of rak'ahs, but if one of you fears morning is near, he should pray one rak'ah which will make his prayer an odd number for him.
The Book of Prayer - Travellers
Sahih Muslim 749a
Hadith Text
Prayer during the night should consist of pairs of rak'ahs, but if one of you fears morning is near, he should pray one rak'ah which will make his prayer an odd number for him.
Commentary
This noble hadith establishes two fundamental principles for the night prayer (Tahajjud). Firstly, the default manner of performing voluntary night prayers is in pairs of rak'ahs, following the prophetic practice of praying two rak'ahs at a time.
Secondly, the wisdom of concluding with an odd number demonstrates the importance of ending the night prayer with Witr. When dawn approaches and time becomes constrained, a single rak'ah suffices to fulfill this obligation, transforming what was prayed in pairs into an odd total.
This teaching reflects the Shariah's balance between maintaining recommended practices and providing ease for the worshipper. The odd number preserves the distinctive character of night worship while accommodating practical circumstances.
Juridical Rulings
The minimum Witr is one rak'ah, though three is preferable. The prohibition against praying Witr as two rak'ahs is established by consensus.
If one fears missing Witr due to sleep or dawn's arrival, it is recommended to pray it before sleeping, following the Prophet's instruction to those concerned about waking up.