One of the Hebrew names of God is El, composed of the Hebrew letters Lamed (representing 30) and Aleph (representing 1), which totals to the number 31.
Josiah, considered the best king of Judah after Israel split into two nations, began his reign at the age of eight and ruled for 31 years (640 to 609 B.C.).
One of the most commonly occurring names in God’s word is Moses, which appears in 31 books. One of most frequently mentioned women in Scripture is Rebekah (Isaac’s wife), whose name appears 31 times. The book of Luke contains materials from 31 Old Testament books, the second highest in the New Testament.