Sayyiduna Ibn Mas'ud (may Allah be pleased with him) said: "Whoever recites the Qur'an receives ten good deeds for every letter of a verse. I do not say that Alif-Lam-Mim equals ten good deeds; rather, Alif, Lam and Mim are thirty good deeds, each separately."
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 8615