In the Old Testament, when God destroyed the earth with water, He caused it to rain 40 days and 40 nights (Genesis 7:12). After Moses killed the Egyptian, he fled to Midian, where he spent 40 years in the desert tending flocks (Acts 7:30). Moses was on Mount Sinai for 40 days and 40 nights (Exodus 24:18). Moses interceded on Israel’s behalf for 40 days and 40 nights (Deuteronomy 9:18, 25). The Law specified a maximum number of lashes a man could receive for a crime, setting the limit at 40 (Deuteronomy 25:3). The Israelite spies took 40 days to spy out Canaan (Numbers 13:25). The Israelites wandered for 40 years (Deuteronomy 8:2-5). Before Samson’s deliverance, Israel served the Philistines for 40 years (Judges 13:1). Goliath taunted Saul’s army for 40 days before David arrived to slay him (1 Samuel 17:16). When Elijah fled from Jezebel, he traveled 40 days and 40 nights to Mt. Horeb (1 Kings 19:8).

In the New Testament, Jesus was tempted for 40 days and 40 nights (Matthew 4:2). There were 40 days between Jesus’ resurrection and ascension (Acts 1:3).