'Certain' in the Bible

Then Gideon was certain that he was the angel of the Lord; and Gideon said, I am in fear, O Lord God! for I have seen the angel of the Lord face to face.

See, I will put the wool of a sheep on the grain-floor; if there is dew on the wool only, while all the earth is dry, then I will be certain that it is your purpose to give Israel salvation by my hand as you have said.

But a certain woman sent a great stone, such as is used for crushing grain, on to the head of Abimelech, cracking the bone.

Now there was a certain man of Zorah of the family of the Danites, and his name was Manoah; and his wife had never given birth to a child.

Then Micah said, Now I am certain that the Lord will do me good, seeing that the Levite has become my priest.

Now in those days, when there was no king in Israel, a certain Levite was living in the inmost parts of the hill-country of Ephraim, and he got for himself a servant-wife from Beth-lehem-judah.