'Certain' in the Bible

God said to Abram, “Know for certain that your descendants will be strangers in a land that is not theirs, where they will be enslaved and oppressed four hundred years.

He came to a certain place and spent the night there, because the sun had set; and he took one of the stones of the place and put it under his head, and lay down in that place.

And it came about at that time, that Judah departed from his brothers and visited a certain Adullamite, whose name was Hirah.

Judah saw there a daughter of a certain Canaanite whose name was Shua; and he took her and went in to her.