Hadith 244
وَحَدَّثَنِي 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)
Sahih Lighairihi (Salim al-Hilali)
Muwatta Malik 244 · Book 5, Hadith 20