صحيح ابن خزيمه
Sahih Ibn Khuzaymah
جماع أبواب الأذان والإقامةChapters on Adhan and Iqamah
(58) بَابُ ذِكْرِ الْأَخْبَارِ الْمُفَسِّرَةِ لِلَّفْظَتَيْنِ اللَّتَيْنِ ذَكَرْتُهُمَا فِي خَبَرِ أَبِي سَعِيدٍ وَأُمِّ حَبِيبَةَChapter 58: Reports explaining the two phrases mentioned in the reports of Abu Sa‘id and Umm Habibah
Hadith Q414
وَالدَّلِيلِ عَلَى أَنَّ النَّبِيَّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ إِنَّمَا أَمَرَ فِي خَبَرِ أَبِي سَعِيدٍ أَنْ يُقَالَ كَمَا يَقُولُ الْمُؤَذِّنُ حَتَّى يَفْرُغَ، وَكَذَاكَ كَانَ يَقُولُ كَمَا يَقُولُ الْمُؤَذِّنُ حَتَّى يَسْكُتَ، خَلَا قَوْلِهِ حَيَّ عَلَى الصَّلَاةِ، حَيَّ عَلَى الْفَلَاحِ
And the explanation of the evidence that the Prophet ﷺ, in the narration of Abu Sa'id (may Allah be pleased with him), commanded that (the one who hears the adhan) should say just as the muezzin says, until he (the muezzin) finishes (the adhan), and you ﷺ would also say just as the muezzin says, until he becomes silent, except for "Hayya 'ala as-Salah" and "Hayya 'ala al-Falah" (for their response).
