Here it refers to their weakness of will-power, carelessness in establishing the religion and lack of courage in face of its enemies. al-Huzn (grief) is opposite of al-farh (joy, happiness); it afflicts a man when he loses a favorite possession, or something which he thinks belongs to him.
Zaidi ya hayo, Qur an Tukufu ni Kitabu kamili na sio pungufu katika hali yeyote, kama ilivyoeleza kabla, na hivyo vipi ingeliweza kuwa kamili bila kuwa na ufunguzi wake. Allah (s.w.t.) Mwenyewe amedai kwamba Yeye (s.w.t.) ameikamilisha dini yetu na ametimiza neema Zake.