(5) باب الأَمْرِ بِإِخْرَاجِ زَكَاةِ الْفِطْرِ قَبْلَ الصَّلاَةِ
Abdullah b 'Umar reported that the Messenger of Allah (ﷺ) ordered the payment of Sadaqat-ul-Fitr before people go out for prayer.
Reference: Sahih Muslim 986 b
In-book reference: Book 12, Hadith 27
USC-MSA web (English) reference(deprecated numbering scheme): Book 5, Hadith 2160