Question: Forty (40) is the mystical number signifying penance. Name three events in which the number 40 is used in Sacred Scripture.
Answer: There are many of them... here are a few:
The Great Flood
Genesis 7:12 For forty days and forty nights heavy rain poured down on the earth.
Moses on the Mountain with God (Receives the 10 Commandments)
Exodus 24:18 But Moses passed into the midst of the cloud as he went up on the mountain; and there he stayed for forty days and forty nights.
Moses on the Mountain with God Again (Receives Second Set of Tablets)
Exodus 34:28 So Moses stayed there with the Lord for forty days and forty nights, without eating any food or drinking any water, and he wrote on the tablets the words of the covenant, the ten commandments.
Israelites spent 40 years in the Wilderness
Numbers 14:33 here where your children must wander for forty years, suffering for your faithlessness, till the last of you lies dead in the desert.
Jonah warned Nineveh
Jonah 3:4 Jonah began his journey through the city, and had gone but a single day's walk announcing, "Forty days more and Nineveh will be destroyed."
Jesus fasts for 40 days in the Wilderness
Matthew 4:2 He fasted forty days and forty nights, and afterward was hungry.
Jesus seen on earth after being crucified.
Acts 1:3 In the time after his suffering he showed them in many convincing ways that he was alive, appearing to them over the course of forty days and speaking to them about the reign of God.