What is the wisdom behind God's testing of children?

Allah may test His servant as an expiation for his sins and a trial for his faith, as stated in the Almighty's verse: "And whatever strikes you of disaster – it is for what your hands have earned." As for the affliction of a child, it carries great wisdom. It may be a test of the parents' patience and their contentment with Allah's decree. The proof for this is what was reported from the Prophet, peace and blessings be upon him, that whoever loses two or three of his children and seeks Allah's reward for them, will enter Paradise. There may also be other wisdoms known only to Allah.