Ruth 1:18
"When she saw that she was stedfastly minded to go with her, then she left speaking unto her."
Cross References (ranked by relevance)
Acts 21:14
And when he would not be persuaded, we ceased, saying, The will of the Lord be done.
Ephesians 6:10
Finally, my brethren, be strong in the Lord, and in the power of his might.
Acts 2:42
And they continued stedfastly in the apostles’ doctrine and fellowship, and in breaking of bread, and in prayers.