Reference is made again to the hired soldiers or mercenaries in Egypt’s army. They are like fattened calves
which could either mean they were very well cared for, or they were like fattened calves ready for slaughter. Either way, they prove to be totally ineffective in battle. They do not stand but rather turn and flee for the day of their calamity has come upon them, the time of their punishment.
The clear implication is that they are facing the Lord’s judgment.
21 Even her hired soldiers in her midst are like fattened calves; yes, they have turned and fled together; they did not stand, for the day of their calamity has come upon them, the time of their punishment.