After them - i. e. “after my maidens.” The fields not being divided by hedges, but only by unplowed ridges, it would be easy for her to pass off Boaz’s land without being aware of it, and so find herself among strangers where Boaz could not protect her.
Related Commentaries of Ruth 2:9
Ruth 2:9
9 Let thine eyes be on the field that they do reap, and go thou after them: have I not charged the young men that they shall not touch thee? and when thou art athirst, go unto the vessels, and drink of that which the young men have drawn.