Sunan Ibn Majah, Volume 5, Book 33, Hadith 3779 (DarusSalam) ⓘ
It was narrated from Aisha that the Messenger of Allah said: "The one who is proficient with the Qur'an will be with the noble and righteous scribes (the angels), and the one who reads it and stumbles over it, finding it difficult, will have a double reward."
حَدَّثَنَا هِشَامُ بْنُ عَمَّارٍ، حَدَّثَنَا عِيسَى بْنُ يُونُسَ، حَدَّثَنَا سَعِيدُ بْنُ أَبِي عَرُوبَةَ، عَنْ قَتَادَةَ، عَنْ زُرَارَةَ بْنِ أَوْفَى، عَنْ سَعْدِ بْنِ هِشَامٍ، عَنْ عَائِشَةَ، قَالَتْ قَالَ رَسُولُ اللَّهِ ـ صلى الله عليه وسلم ـ " الْمَاهِرُ بِالْقُرْآنِ مَعَ السَّفَرَةِ الْكِرَامِ الْبَرَرَةِ وَالَّذِي يَقْرَؤُهُ يَتَتَعْتَعُ فِيهِ وَهُوَ عَلَيْهِ شَاقٌّ لَهُ أَجْرَانِ اثْنَانِ " .
also referenced under: Hadith 3779 (Reference) & Book 33, Hadith 124 (In-Book)