Reported by Abu Dharr (RA): The Prophet (peace be upon him) said, “In the morning, charity is due on every joint bone of the body of everyone of you. Every utterance of Allah’s glorification (i.e. saying Subhan Allah) is an act of charity, and every utterance of His praise is (saying Alhamdulillah) is an act of charity and every utterance of declaration of His Greatness (i.e. saying La ilaha illAllah) is an act of charity, and enjoining Ma’ruf (good) is an act of charity, and forbidding Munkar (evil) is an act of charity, and two Rak’ah Duha prayers which one performs in the forenoon is equal to all this (in reward).
[Muslim - Riyad us Saliheen Chapter 206, 1140]