Sahih Muslim , Book 4, Hadith 217 (In-Book) ⓘ
Anas reported: The Messenger of Allah would listen to the crying of a lad in the company of his mother, in prayer, and he would recite a short surah or a small surah.
وَحَدَّثَنَا يَحْيَى بْنُ يَحْيَى، أَخْبَرَنَا جَعْفَرُ بْنُ سُلَيْمَانَ، عَنْ ثَابِتٍ الْبُنَانِيِّ، عَنْ أَنَسٍ، قَالَ أَنَسٌ كَانَ رَسُولُ اللَّهِ صلى الله عليه وسلم يَسْمَعُ بُكَاءَ الصَّبِيِّ مَعَ أُمِّهِ وَهُوَ فِي الصَّلاَةِ فَيَقْرَأُ بِالسُّورَةِ الْخَفِيفَةِ أَوْ بِالسُّورَةِ الْقَصِيرَةِ .
also referenced under: Hadith 470 (Reference) & Book 4, Hadith 951 (USC-MSA)