No creature can precisely know this moment, except for the wicked prophet Balaam, about whom the Torah says, "one who knows the mind of the Supreme One." But how could that be? Balaam did not even know the mind of an animal!
When the Moabite emissaries saw Balaam riding on a donkey, they asked him, "Why do you not ride a horse?" He answered, "Usually I ride a horse. Today I am riding a donkey for the first time, because I put my horses in the marshland to graze."
The she-donkey said to him, "Am I not your she-donkey?" Balaam said, "To carry loads." She, however, replied, "That you have ridden on me." He said, "Occasionally," and she replied, "All your life until this day! And not only that, but I provide you with riding by day and with marital acts at night!"
Rather, Balaam knew the moment when God was angry and was trying to say the word "kelim," or "destroy them," at this moment, but it became "Melech," or "king," in his mouth.
Art: Taming The Donkey by Eduardo Zamacois y Zabala