Albert Barnes Commentary Matthew 20:9

"And when they came that [were hired] about the eleventh hour, they received every man a shilling." — Matthew 20:9 (ASV)

They received every man a penny. There was no agreement how much they should receive, but merely that justice should be done (Matthew 20:4, 5, 7).

The householder supposed they had earned it, or chose to make a present to them to compensate for the loss of the first part of the day, when they were willing to work but could not find employment.