'Unforeseen' in the Bible

Let {unforeseen ruin} come on him, and his net that he hid, let it catch him. Let him fall into it in ruin.

While they are saying, “Peace and safety [all is well and secure!]” then [in a moment unforeseen] destruction will come upon them suddenly like labor pains on a woman with child, and they will absolutely not escape [for there will be no way to escape the judgment of the Lord].