The Meaning of Numbers: The Number 10,000
The number 10,000 derives part of its Bible meaning from the fact that it is sometimes used to denote a group that is innumerable or countless (see Paul and Revelation's use below). It also has a relationship with several Judges of Israel.
Haman, Prime Minister of Persia, was willing to pay the empire's king 10,000 talents of silver (worth around $180 million today) to defray the cost of murdering all the Jews in the kingdom (Esther 3:9)!
Deborah, a prophetess who was Israel's Judge, summons a man named Barak. Inspired by God, she charges him with gathering 10,000 men to fight King Jabin's army in order to free Israel of his twenty-year oppression (Judges 4:1 - 7, 14). Barak agrees to lead the army into battle only if Deborah comes with him (verse 8). After Israel defeats their oppressor the people enjoy forty years of peace (5:31).
Appearances of the number ten thousand
Gideon is called by God to free his people from Midianite domination. He sends messengers to four Israelite tribes asking men to volunteer to fight Midian (Judges 6:1 - 35).
About 32,000 men come to Gideon, far more than God is willing to use to defeat the enemy. Those who are afraid or fearful are told to go back home, leaving an army of ten thousand (Judges 7:2 - 3). The army is still too large for the Eternal, and it is ultimately whittled down to only 300 before it can win a mighty victory (verses 4 - 7).
God called Ehud, a rare left-handed warrior, to save his people from the oppression of the Moabites (Judges 3:12 - 15). After killing Eglon, Moab's king, Ehud rallies the Israelites to fight against their enemies. The King James Bible then states something odd about the Moabites who were killed.
And they (the Israelites) slew of Moab at that time about ten thousand men, ALL LUSTY, and all men of valor; and there escaped not a man (Judges 3:29, KJV).
The Hebrew word shamen (Strong's Concordance #H8082), translated "lusty" above, means someone who is gross, fat, rich, greasy or even robust!
Paul's use of the number 10,000
For you might have ten thousand tutors in Christ, but you do not have many fathers; for in Christ Jesus I did beget you through the gospel (1Corinthians 4:15).
Apostle Paul, several chapters later, again uses 10,000 to illustrate a point. He utilizes it to show the overwhelming importance of speaking words that others can understand versus the overrated gift of speaking in tongues (other languages).
But in the church, I desire to speak five words with my understanding rather than ten thousand words in an unknown language, so that I may also instruct others (1Corinthians 14:19).
Additional info on the Biblical Meaning of 10,000
In the Bible, 10,000 is used in its last book to describe the vast quantity of righteous spirit beings that surround the Eternal's throne. If taken literally, the verse in question is likely delineating the largest number recorded in God's word!
And I beheld, and I heard the voice of many angels round about the throne and the beasts and the elders: and the number of them was ten thousand times ten thousand, and thousands of thousands (Revelation 5:11, KJV).