'Ascertained' in the Bible

Thereupon Herod sent privately for the Magi and ascertained from them the exact time of the star's appearing.

Then Herod, finding that the Magi had trifled with him, was furious, and sent and massacred all the boys under two years of age, in Bethlehem and all its neighbourhood, according to the date he had so carefully ascertained from the Magi.