Sayyiduna Abdullah bin Amr (may Allah be pleased with them both) said that the Messenger of Allah (peace and blessings be upon him) said: "There are forty good qualities, the best of all of which is giving a milch animal (on loan). No servant acts upon any one of these qualities, hoping for its reward and believing in what is promised, except that Allah will admit him into Paradise."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الزكاة / 7799