And so the two went on, till they met a young man, and the sage slew him. At this Moses exclaimed, ‘Have you slain an innocent human being without his having taken another man’s life? Indeed, you have done a terrible thing!’
Moses speaks from his conscience again, and invokes a law that permits the taking of life under certain circumstances. Such laws generally reflect the severity of the threat posed by their infraction to the maintenance of a viable society and the health of the human soul. However, as far as Moses knows, there is no reason to kill the young man. Here Khidr has progressed from destruction of property and the creation of a hypothetical danger, to unprovoked murder. No matter how compelling Moses’ desire for divine knowledge, or how firm his intention to maintain silence under any circumstance – to be "a good boy," and obedient to authority – he is compelled even more strongly to be "a good man," obedient to his own conscience, speaking out in a timely manner in response to what his knowledge of the law tells him is an extreme injustice.
If Moses is being tested on his capacity to disregard the murder of an innocent soul, Moses is doomed to fail.
But if Moses is being tested on his understanding of moral law, then Moses has passed the test.
He replied, ‘Did I not tell you that you will never be able to have patience with me?’
Yet again we encounter "I told you so"; and a repetition of the unequivocal never.
If the test is a test of Moses’ capacity for silent compliance in the face of evident brutality, we have just been reminded for the third time by Khidr that the rational, compassionate and just Moses will always fail.
Moses said, ‘If after this I should ever question you, dismiss me from your company; by now, you have heard enough excuses from me.’
Moses has every good intention, and humility as well. He is accustomed to a world in which those who question authority – no matter how unreasonable that authority may be – do not last long. He knows he’s not living up to his part of the bargain as he understands it, and Khidr has made it clear that he never would be able to anyway. But he presses on, determined to gain some understanding from this mysterious carrier of divine wisdom, even if it’s a Sisyphean task.
If Moses is being tested on his capacity for humility, perseverance, and honest acknowledgment of his human limitations, then Moses has passed the test.