The Prophet ﷺ said: He who leaves the Friday prayer (continuously) for three Friday on account of slackness, Allah will print a stamp on his heart. (Using translation from Abū Dāʾūd 1052)
أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ «مَنْ تَرَكَ ثَلَاثَ جُمِعٍ تَهَاوُنًا بِهَا طَبَعَ اللَّهُ عَلَى قَلْبِهِ»