Sunnah.com reference : Book 2, Hadith 382English translation : Book 2, Hadith 459Arabic reference : Book 2, Hadith 462
Narrated Abu Hurairah (RA):
Allah's Messenger (ﷺ) said: "Whoever takes a bath, then comes to al-Jumu'ah prayer, then prays what was fixed for him, then keeps silent till the Imam finishes the Khutbah (religious talk - sermon), and then prays along with him - his sins (committed) between that time and the next Friday will be forgiven, with an addition of three days more."

[Reported by Muslim].
وَعَنْ أَبِي هُرَيْرَةَ ‏- رضى الله عنه ‏- قَالَ: قَالَ رَسُولُ اَللَّهِ ‏- صلى الله عليه وسلم ‏-{ مَنِ اغْتَسَلَ, ثُمَّ أَتَى الْجُمُعَةَ, فَصَلَّى مَا قُدِّرَ لَهُ, ثُمَّ أَنْصَتَ, حَتَّى يَفْرُغَ اَلْإِمَامُ مِنْ خُطْبَتِهِ, ثُمَّ يُصَلِّي مَعَهُ: غُفِرَ لَهُ مَا بَيْنَهُ وَبَيْنَ الْجُمُعَةِ اَلْأُخْرَى, وَفَضْلُ ثَلَاثَةِ أَيَّامٍ }  رَوَاهُ مُسْلِم ٌ  1‏ .‏‏1 ‏- صحيح.‏ رواه مسلم (857)‏ (27)‏.‏