The Meaning of Numbers: The Number 31
Part of the meaning of the number 31 comes from one of the Hebrew names for God. Gematria is a way of interpreting Scripture by substituting the letters of a Hebrew (or Greek) word by their equivalent numeric values and arriving at a total. One reference to God is El (see Deuteronomy 32:15, 17, Job 3:4, etc. in Hebrew), which is composed of the Hebrew letters Lamed and Aleph. Their numeric values are 30 and 1, respectively, for a total of 31.
One of the most commonly occurring names in God's word is Moses. It appears in 31 Biblical books.
One of most frequently mentioned Biblical women is Rebekah, the wife of the patriarch Isaac. Her name is recorded thirty-one times.
Appearances of the number thirty-one
Josiah (2Kings 22:1), considered the best kings of Judah after Israel split into two nations, began his reign at the age of eight and ruled for thirty-one years (from 640 to 609 B.C.).
The 31st patriarch in Jesus' lineage is Obed, the father of Jesse. It was Jesse who gave birth to King David in 1040 B.C.
Josiah was 31 years old when he gave birth to Zedekiah (1Chronicles 3:15). He would assume the throne over the Kingdom of Judah in 597 at the age of 21 (2Kings 24:18). Zedekiah is important to Biblical history as he is the last human to rule over either Israel or Judah. His rule ended in 586 when the Babylonians conquered Jerusalem and burned the temple.
Surprisingly, there are no months in the Biblical (Hebrew) calendar that contain 31 days! Five of them always have twenty-nine days, two can have twenty-nine or thirty, and the rest always contain thirty. Compare this to our Gregorian-based calendar which always has seven months with thirty-one days.
The number 31 and the Promised Land
Moses, before his death, aided the Israelites in conquering two kings east of the Jordan (Joshua 12:1 - 6). They were Amorite King Sihon and Og, king of Bashan. Og was especially noteworthy as he was the last of the Rephaim (giants). Scripture states his bed was 13 1/2 feet long (4.1 meters) by 6 feet (1.8 meters) wide (Deuteronomy 3:11)!
The children of Israel, however, under the leadership of Joshua, conquered 31 kings west of the Jordan River. These kings were defeated, and land confiscated, toward the goal of fully possessing the Land of Promise (Joshua 12:24).
Additional info on the Biblical Meaning of 31
In 31 A.D., the first year after Jesus' death and resurrection, the gospel is already being preached in Jerusalem. The apostles, in this year, also begin the long task of compiling his teaching (Acts 5 and 6).
The book of Luke contains references to thirty-one Old Testament books, the second highest number in the New Testament.