Jehovah-nissi means the LORD who is my Banner.
The story behind the name comes just after the Exodus. A people called the Amalekites made the very bad mistake of attacking the children of Israel at a place called Rephidim(Exodus 17:8). Joshua led the people into battle while Moses went up the hill. There he raised the staff, a symbol of GOD's authority and power in the air. As long as he held this staff in the air the Israelites would continue to win. But when his arms grew tired they would be pushed back. Finally, his brother and Hur helped Moses to hold the staff steady till sunset. Thus the Israelites triumphed.
Some of you may wonder about the present day significance of this.
Consider this...
Jesus was lifted up for us. HE is our banner and from whom we get our strength and authority on this earth. It is by the power of HIS Holy Spirit that we are empowered to the acts of GOD that HE has prepared beforehand for us.When we look up to him and raise HIM as LORD over our lives we can go forth as the victors that HIS shed blood made us.
...in all things we are more than conquerors through him who loved us.(Rom 8:37)
Are you in a battle today? Then look up to HE who is your Banner, Jesus. Raise HIS banner high and live victoriously.