Sayyiduna Abu Dharr (may Allah be pleased with him) said that some of the Companions of the Messenger of Allah (peace and blessings be upon him) said to him: "The people of wealth have surpassed us in reward, for they pray as we pray, they fast as we fast, and they give charity from their surplus wealth." He (peace and blessings be upon him) said: "Has Allah not made for you something with which you can give charity? Every glorification (tasbih) is charity, every takbir is charity, every tahlil and tahmid is charity, enjoining good is charity, forbidding evil is charity, and even in the intimate relations of one of you there is charity." They said: "O Messenger of Allah (peace and blessings be upon him), when one of us fulfils his desire, is that charity and is there a reward for him?" He (peace and blessings be upon him) said: "If he were to place it in something unlawful, would there not be a sin upon him?" They said: "Of course." He (peace and blessings be upon him) said: "Likewise, when he places it in what is lawful, there will be a reward for him."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الزكاة / 7823