always having to be ready to obey someone's orders immediately唯某人之命是從，隨時聽候某人的差遣
at (one's) beck and call
Ready to comply with any wish or command.唯命是從：愿意依從任何愿望或命令
柯林斯高階英漢雙解學習詞典釋義
PHRASE
聽憑…調遣；聽命于…
If one person is at another's beck and call, they have to be constantly available and ready to do whatever is asked, and this often seems unfair or undesirable.