صحيح ابن خزيمه
Sahih Ibn Khuzaymah
Chapter 26
(400) بَابُ الدَّلِيلِ عَلَى أَنَّ الْمُدْرِكَ هَذِهِ الرَّكْعَةَ مُدْرِكٌ لِوَقْتِ الصَّلَاةِ وَالْوَاجِبُ عَلَيْهِ إِتْمَامُ صَلَاتِهِ
400 Chapter: Evidence That Catching This Unit Means Catching the Prayer Time and the Obligation to Complete the Prayer.
1 hadith
Hadith 986
It is narrated from Sayyiduna Abu Hurairah (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "Whoever has prayed one rak'ah in the morning and then the sun rises, he should complete it by praying the second rak'ah with it."