“One who memorizes Quran with difficulty will get two rewards and one who memorizes it with ease would be included among the virtuous.” ...

Imām Ja'far ibn Muhammad al-Sādiq (a.s.)
Sawab al-A`amal, Page 141
“A person who memorizes the Holy Quran and obeys its commandments is in the group of senior angels.”
Imām Ja'far ibn Muhammad al-Sādiq (a.s.)
Sawab al-A`amal, Page 142
“One who tries to memorize the Holy Quran with extreme difficulty due to a weak memory will get two rewards.” He further said, “Why don’t the people who trade in markets whole day not recite a Surah when they return to their homes at night before going to bed? If they do so they would get ten rewards for each verse and ten sins will be wiped off.”
Imām Ja'far ibn Muhammad al-Sādiq (a.s.)
Sawab al-A`amal, Page 143
“One who memorizes a Surah of Quran and then forgets it, this Surah will appear on an elevated place on the Day of Judgment with a beautiful look. When the person will look at it, he will ask: Who are you? You are so beautiful that I would have loved to own you. It will reply: Didn’t you recognize me? I am so and so Surah. If you hadn’t forgotten me, I would have elevated you also to this position.”
Imām Ja'far ibn Muhammad al-Sādiq (a.s.)
Iqbal al-A`amal, page 301
“One who recites a hundred verses in Salaat-e-Shab, Allah would note down the reward of offering Salaat for the whole night for him and one who recites two hundred verses at night apart from Salaat-e-Shab, the Almighty Allah would write a Qintar of good deeds on Lauh-e-Mahfuz. A single Qintar is equal to twelve hundred Awqiya and a single Awqiya is bigger that Mount Ohad.”
Imām Ja'far ibn Muhammad al-Sādiq (a.s.)
Sawab al-A`amal, Page 142
One who recites in Watr Prayer Surah Falaq and Surah Naas with Surah Tauheed, it is said to him: O Servant of Allah! Congratulations! Allah has accepted your Midnight Prayer.
Imām Muhammad ibn ‘Alī al-Baqir (a.s.)
Sawab al-A`amal, Page 175