previously, I had heard a tradition from Imam Sadeq(Sadiq) (a.s.) regarding looking at non-mahrams that:
«النّظرة سهمٌ من سهام إبلیس مسمومٌ من ترکها للّه لا لغیره أعقبه اللّه إیماناً یجد طعمه»
Looking (at non-mahrams) is a poison arrow from Satan's arrows, whoever leaves it for the sake of Allah not for the sake of others (except him), Allah will give him a faith (Iman) that he tastes its flavor.
I wonder what is its reference?