A powerful question… “Who shall separate us from the love of Christ? Shall tribulation, or distress, or persecution, or famine, or nakedness, or peril, or sword?” - Romans 8:35 (KJV)
They were envious.
“These last men have worked only one hour, and you made them equal to us who have borne the burden and the heat of the day.”
- Matthew 20:12 (NKJV)