3 occurrences across the corpus

King James Version

Genesis 43:3

And Judah spake unto him, saying, The man did solemnly protest unto us, saying, Ye shall not see my face, except your brother be with you.

1 Samuel 8:9

Now therefore hearken unto their voice: howbeit yet protest solemnly unto them, and shew them the manner of the king that shall reign over them.

1 Corinthians 15:31

I protest by your rejoicing which I have in Christ Jesus our LORD, I die daily.