Anas bin Malik (may Allah be pleased with him) narrates that the Prophet (peace and blessings be upon him) drew some lines and drew one line off to one side, then he (peace and blessings be upon him) said: "Do you know what this is? This is the likeness of the son of Adam and his wishes, and this line is his hope; he goes on hoping, and then death overtakes him."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب صلاة الاستسقاء / 6505