'Solemnly' in the Bible

The Lord's angelic messenger went up from Gilgal to Bokim. He said, "I brought you up from Egypt and led you into the land I had solemnly promised to give to your ancestors. I said, 'I will never break my agreement with you,

Whenever they went out to fight, the Lord did them harm, just as he had warned and solemnly vowed he would do. They suffered greatly.

Later, after the two months were concluded, she returned to her father, and he fulfilled what he had solemnly vowed and she never married. That's how the custom arose in Israel

When he gave back to his mother the eleven hundred pieces of silver, his mother said, "I solemnly dedicate this silver to the Lord. It will be for my son's benefit. We will use it to make a carved image and a metal image."