'Solemnly' in the Bible

Therefore,' {declares} Yahweh the God of Israel, 'though I solemnly said that your house and the house of your ancestor would walk before me forever, but now,' {declares} Yahweh, 'far be it from me, for those who honor me I will honor, but those who despise me, I will treat with contempt!

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.

Then, one of the troops said, “Your father made the troops solemnly swear, ‘The man who eats food today is cursed,’ and the troops are exhausted.”