'First born' in the Bible

and the name of his firstborn son was, Joel, and the name of his second, Abijah, - they were judges in Beer-sheba.

And the sons of Saul were Jonathan, and Ishvi, and Malchishua, - and, the names of his two daughters, were, the name of the firstborn, Merab, and, the name of the younger, Michal, -

And the three eldest sons of Jesse had followed Saul to the battle, - and, the names of his three sons who went into the battle, were Eliab the firstborn, and, the next to him, Abinadab, and, the third, Shammah.