that the Messenger of Allah ﷺ said: "Indeed for everything there is a heart, and the Qur'an's heart is Ya Sin. Whoever recites Ya Sin, then for its recitation, Allah writes for him that he recited the Qur'an ten times."  

قَالَ النَّبِيُّ ﷺ إِنَّ لِكُلِّ شَيْءٍ قَلْبًا وَقَلْبُ الْقُرْآنِ يس وَمَنْ قَرَأَ يس كَتَبَ اللَّهُ لَهُ بِقِرَاءَتِهَا قِرَاءَةَ الْقُرْآنِ عَشْرَ مَرَّاتٍ  

Another chain of narration similar in meaning.  

عَنِ النَّبِيِّ ﷺ نَحْوَهُ بِمَعْنَاهُ