Burayda reported,
The Prophet ﷺ was delivering a sermon when Hasan and Husayn 
came along, wearing red shirts and stumbling as they walked. The Prophet ﷺ descended from the pulpit, broke off his speech, picked them up, then returned to the pulpit and said, "Allah has spoken truly, 'Your wealth and your children are only a trial' [Taghabun 64:15]. I saw these two stumbling in their shirts and could not bear it until I interrupted my speech and picked them up."
Nasai 1414
Hasanأخبرنا محمد بن عبد العزيز قال حدثنا الفضل بن موسى عن حسين بن واقد
عن عبد الله بن بريدة عن أبيه قال
كان النبي ﷺ يخطب فجاء الحسن والحسين رضي الله عنهما وعليهما قميصان أحمران يعثران فيهما فنزل النبي ﷺ فقطع كلامه فحملهما ثم عاد إلى المنبر ثم قال صدق الله {إنما أموالكم وأولادكم فتنة} رأيت هذين يعثران في قميصيهما فلم أصبر حتى قطعت كلامي فحملتهما
Its chain of transmission is hasan. Abu Dawud narrated it in the chapter on prayer, in the section on the imam interrupting the sermon for a matter that arises, hadith no. 1109, and Tirmidhi narrated it in the chapter on virtues, in the section on his forbearance and his placing Hasan and Husayn in front of him, hadith no. 3774, from the hadith of Husayn bin Waqid with this wording, and Tirmidhi said, hasan gharib. It is also found in Kubra, hadith no. 1731, and Tabari graded it sahih in his Tafsir, 28/81.