Two of the most commonly repeated numbers in the Bible are 7 and 40. Besides it rained 40 days and 40 nights, what are other examples of the number 40?
Some of the examples of the number 40 being used in the Bible may signify that it is a number of completion, like the number seven. For instance, Moses is on Mount Sinai with God for 40 days and 40 nights (Exodus 24:18). He did a total faster food and water for 40 days and 40 nights while on the mountain in the presence of the Lord (Deuteronomy 9:9).
When he sees the sin of the Israelites in making the golden calf as an idol he intercedes for them for 40 days and 40 nights (Deuteronomy 9:18). Jesus spends time with God as he fasts in the wilderness before the devil tempts him and he begins his ministry (Luke 4:2).
The Israelites traveled in the wilderness for 40 years (Deuteronomy 8:4; Acts 13:18). This is how long it took the Israelites to travel even though they could’ve been to the Promised Land in about three weeks. Because of their disobedience, they spent 40 years in the wilderness and the first generation of Israelites died there. God gave Nineveh 40 days to repent before he would destroy the city (Jonah 3:4).
A person was allowed to endure 40 lashes with a whip for punishment (Deuteronomy 25:3). Moses said anything beyond this and the person’s life would be in jeopardy. It’s possible Jesus endured this before he went to the cross. Paul mentions having been whipped five times 39 lashes by saying the 40 minus one as he suffered for the gospel (2 Corinthians 11:24).
Sometimes the number 40 doesn’t sound significant but it can give witness to God’s grace and mercy, his provision. For instance, the Israelites ate manna from heaven all 40 years they were in the wilderness (Exodus 18:35; Deuteronomy 2:7). This shows that God provided for them the whole time they were in the wilderness.
Other times the number 40 may not have much spiritual or theological significance. Isaac married Rebecca when he was 40 years old (Genesis 25:20). Esau married Judith when he was 40 years old (Genesis 28:34).
The Egyptian practice of embalming took 40 days (Genesis 50:3). The Israelite spies spy out the land of Canaan for 40 days (Number is 13:25). Several judges of Israel ruled for 40 years (Judges 3:11; 5:31; 8:28). Eli the priest judged Israel for 40 years (1 Samuel 4:18).
Goliath challenged Israel to a duel for 40 days (1 Samuel 17:16). David rained in Israel for 40 years (2 Samuel 5:4; 1 Kings 2:11). Solomon also ruled Israel for 40 years (1 Kings 11:40). It took Elijah 40 days and 40 nights to get to Mount Horeb to meet with God during his depression (1 Kings 19:8).
So sometimes the number 40 is extremely significant in the Bible as for the first examples. Other times it may not mean anything at all. I think sometimes we decide for ourselves if the number means anything significant. But there were times that the Bible clearly displayed a theological reason for using the number 40.