'Firmly' in the Bible

He answered, “Because of your little faith [your lack of trust and confidence in the power of God]; for I assure you and most solemnly say to you, if you have [living] faith the size of a mustard seed, you will say to this mountain, ‘Move from here to there,’ and [if it is God’s will] it will move; and nothing will be impossible for you.

and said, ‘For this reason a man shall leave his father and mother and shall be joined inseparably to his wife, and the two shall become one flesh’?

"Friend," said Jesus, "carry out your intention." Then they came and laid their hands on Jesus and seized Him firmly.