The Israelites were unable to withstand the intensity of the direct revelation, and their souls left them. God then spoke to them pleasantly and lovingly, and their souls returned.

This is comparable to a king who spoke harshly to his son, and the son was afraid and his soul almost departed from him. When the king saw his soul had departed, he began to caress and kiss him and to comfort him, telling him: What is the matter? Aren’t you my only son? Am I not your father? So too, when the Holy One, blessed be He, spoke and said: “I am the Lord your God” (Exodus 20:2) – immediately the Israelites’ souls left them. When they died, the angels began caressing and kissing them, and told them: What is the matter? Do not fear, “you are children to the Lord your God” (Deuteronomy 14:1). The Holy One, blessed be He, spoke sweetly to them, telling them: Aren’t you My children? I am the Lord your God. You are My people. You are beloved before Me. He began comforting them until their souls returned and they began requesting an additional revelation from Him…. When their souls left them, the Torah began asking for mercy for Israel from the Holy One, blessed be He. It said before Him: Master of the Universe, is there a king who marries off his daughter and concurrently kills a member of his household? I am likened to Your daughter, and the entire world is joyful on my account. Yet Your children are dying. Immediately, the Israelites’ souls returned. That is what is written: “The Torah of the Lord is perfect, restoring the soul” (Psalms 19:8). (Shir HaShirim Rabba 6)