Surah 2. Al-Baqara, Ayah 162

Therein - in the curse. A curse is not a matter of words: it is a terrible spiritual state, opposite to the state of Grace. Can man curse? Not of course in the same sense in which we speak of the curse of God. A mere verbal curse is of no effect. Hence the English saying: "A causeless curse will not come." But if men are oppressed or unjustly treated, their cries can ascend to God in prayer, and then it becomes God's "wrath" or curse, the deprivation of God's Grace as regards the wrong-doer.