'Certain' in the Bible

And there was a certain man of Ramathaim-zophim, of mount Ephraim, and his name was Elkanah, the son of Jeroham, the son of Elihu, the son of Tohu, the son of Zuph, an Ephrathite.

And Saul said to his uncle, He told us for certain that the asses were found. But of the matter of the kingdom, of which Samuel had spoken, he told him not.

(Now a certain man of the servants of Saul was there that day, detained before Jehovah; and his name was Doeg, the Edomite, chief of the shepherds that belonged to Saul.)

Then said David, Jehovah, God of Israel, thy servant hath heard for certain that Saul seeketh to come to Keilah, to destroy the city for my sake.