The angels hastened to indict [Ishmael], exclaiming: "Master of the Universe! Would You bring up a well for one who will one day slay Your children with thirst?" "What is he now," asked G-d "righteous or wicked?" "Righteous," said the angels. Said G-d: "I judge man only as he is at the moment."
Midrash Rabbah on Genesis 21:17
