Muwatta Malik 244
موطأ مالك#244Sahihوَحَدَّثَنِي عَنْ مَالِكٍ، عَنْ صَفْوَانَ بْنِ سُلَيْمٍ، - قَالَ مَالِكٌ لاَ أَدْرِي أَعَنِ النَّبِيِّ صلى الله عليه وسلم أَمْ لاَ - أَنَّهُ قَالَ " مَنْ تَرَكَ الْجُمُعَةَ ثَلاَثَ مَرَّاتٍ مِنْ غَيْرِ عُذْرٍ وَلاَ عِلَّةٍ طَبَعَ اللَّهُ عَلَى قَلْبِهِ " .
Yahya related to me from Malik that Safwan ibn Sulaym said, "If anyone omits jumua three times without reason or illness, Allah will set a seal on his heart." (Malik said, "I don't know if it was from the Messenger of Allah, may Allah bless him and grant him peace, or not)
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:
In-book reference: 5:20