This video introduces ‘ketiv qere’ – instances where the Masoretes noted the correct reading of a word in the margin of the text. A ketiv qere occurs in Ruth 1:8. This video is a little longer than normal.
For those who are interested in learning what the marginal notes mean in the BHS, Page Kelley has written a helpful book:
Page H. Kelley, Daniel S. Mynatt, and Timothy G. Crawford. The Masorah of Biblia Hebraica Stuttgartensia. Grand Rapids: Eerdmans, 1998.