Hazrat Shaikh Moulana Muhammad Zakariyya (rahmatullahi ‘alaih) once mentioned:
From my childhood days, I have seen many debates among the ‘Ulama concerning whether the Shia are able to memorize the Quraan or not. On one occasion, some non-Muslims and Shia got together and intended to pay a Muslim (who was a haafiz of the Quraan) a large sum of money, on the condition that he presents himself as a Shia and recites the Quraan by memory (since there were no Shia that were haafiz of the Quraan). On the day of the debate, the Muslim (who was paid to act as a Shia) arrived. He told the audience that he was a Shia and began to revile and curse the Sahaabah (radhiyallahu ‘anhum) in the presence of the entire gathering. As soon as he began cursing and reviling the Sahaabah (radhiyallahu ‘anhum), the Quraan was immediately erased from his heart and Allah Ta’ala deprived him of the blessing of the Quraan. Hazrat Shaikh (rahmatullahi ‘alaih) addressing the audience then said: Beloved friends! This is the disastrous outcome of showing disrespect (to the Sahaabah radhiyallahu ‘anhum). (Malfoozaate Hazrat Shaikh 1/38)
Source: Ihyaauddeen.co.za