Justices used to be nominated & confirmed and then offered the position…

"identifies eight Supreme Court nominees who subsequent to Senate confirmation did not assume the office to

which they had been appointed: Seven declined the office, and one died before assuming it. It should be noted,

however, that one of the seven who declined the office, William Cushing—confirmed to be Chief Justice in 1796—was

at the time serving on the Court as an Associate Justice, and continued to serve in that capacity until 1810. Another of

the seven, John Jay—confirmed to be Chief Justice in 1800—had served earlier on the Court, as the Court’s first Chief

Justice, from 1789 to 1795."

https://fas.org/sgp/crs/misc/RL33225.pdf