Sunan Abi Dawud 1326
سنن أبي داود#1326SahihNarrated 'Abdullah bin 'Umar:A man asked the Messenger of Allah (ﷺ) about the prayer at night. The Messenger of Allah (ﷺ) said: Prayer during the night should consist of pairs of rak'ahs, but if one of you fears the morning is near he should pray one rak'ah which will make his prayer an odd number for him
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Al-AlbaniSahih
Muhammad Muhyi Al-Din Abdul HamidSahih
Shuaib Al ArnautSahih
Zubair Ali ZaiSahih Bukhari (990) Sahih Muslim (749)
In-book reference: 5:77