'Oldest' in the Bible

So Abraham instructed his servant, who was the oldest member of his household and in charge of everything he owned, "Make this solemn oath to me

Judah found a wife for his oldest son Er. Her name was Tamar.

But the LORD considered Er, Judah's oldest son, to be wicked so he put him to death.

The palace manager searched for the cup, beginning with the oldest brother's sack and ending with the youngest brother's sack, and there it was! in Benjamin's sack.

The three oldest sons of Jesse followed Saul into battle. The names of his three sons who went to the battle were his firstborn Eliab, Abinadab, his second son, and Shammah, the third.

David was the youngest, while the three oldest had followed Saul.

Eliab his oldest brother heard him talking to the men. Eliab was angry with David and said, "Why did you come down here? And who did you leave those few sheep with in the wilderness? I know your insolence and wicked intentions. You came down just to see the battle!"

Some time later, when his children were celebrating in their oldest brother's house,

While this messenger was still speaking, another came and announced, "Your children were celebrating in their oldest brother's house

When they heard this, they went away one by one, beginning with the oldest, and he was left alone with the woman standing there.