The Book of Eclipses
16/23. Chapter:
How is the Khutbah delivered during an eclipse?
Sunan an-Nasai
أَخْبَرَنَا أَحْمَدُ بْنُ سُلَيْمَانَ، قَالَ حَدَّثَنَا أَبُو دَاوُدَ الْحَفَرِيُّ، عَنْ سُفْيَانَ، عَنِ الأَسْوَدِ بْنِ قَيْسٍ، عَنْ ثَعْلَبَةَ بْنِ عِبَادٍ، عَنْ سَمُرَةَ، أَنَّ النَّبِيَّ صلى الله عليه وسلم خَطَبَ حِينَ انْكَسَفَتِ الشَّمْسُ فَقَالَ " أَمَّا بَعْدُ " .
It was narrated from Samurah that: The Prophet (ﷺ) delivered a Khutbah when the sun eclipsed and he said: 'Amma ba'd (to proceed).'"
Reference : Sunan an-Nasa'i 1501In-book reference : Book 16, Hadith 43English translation : Vol. 2, Book 16, Hadith 1502