Sahih Muslim 2288
صحيح مسلم#2288Sahihحَدَّثَنَا يَحْيَى بْنُ يَحْيَى، أَخْبَرَنَا أَبُو خَيْثَمَةَ، عَنْ مُوسَى بْنِ عُقْبَةَ، عَنْ نَافِعٍ، عَنِ ابْنِ عُمَرَ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم أَمَرَ بِزَكَاةِ الْفِطْرِ أَنْ تُؤَدَّى قَبْلَ خُرُوجِ النَّاسِ إِلَى الصَّلاَةِ .
Ibn 'Umar reported that the Messenger of Allah (ﷺ) ordered that the Sadaqat-ul-Fitr should be paid before the people go out for prayer
Scholarly Authentication
The label above is the grade most of these scholars gave — one dissenting opinion no longer speaks for all of them. If any scholar calls a narration fabricated, that verdict is shown instead, whatever the others say. Each scholar's own wording:
Every narration in Sahih Muslim is accepted as Sahih (authentic) by the established status of the book.
In-book reference: 12:26