Rejoice in the Lord

I've read that "rejoice" in the Greek language literally means "to boast". As David Jeremiah points out "Normally, boasting has a negative connotation -- its sounds arrogant or prideful. But in the New Testament it is used in the sense of boasting in Christ (2 Corinthians 12: 9). The prophet Jeremiah says it as well as anyone:"

23 This is what the LORD says:
"Let not the wise man boast of his wisdom
or the strong man boast of his strength
or the rich man boast of his riches,

24 but let him who boasts boast about this:
that he understands and knows me,
that I am the LORD, who exercises kindness,
justice and righteousness on earth,
for in these I delight,"
declares the LORD.

Jeremiah 9: 23-24 (NIV)