Sayyiduna Abdullah bin Amr bin al-As (may Allah be pleased with them both) said that the Messenger of Allah (peace and blessings be upon him) said: "There are forty good deeds, the highest of which is lending a milch she-goat. No man acts upon any one of them, hoping for its reward and believing in what is promised for it, except that Allah Almighty will admit him into Paradise because of it." Hassan (may Allah have mercy on him) said: Then we set about counting returning the greeting, removing a stone (from the path), and other such good deeds that are below lending a milch she-goat, but we could not get beyond fifteen.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الزكاة / 7798