Found the following hamletworks.org entries referring to line 851

View Commentary Note for 842
842 Ham. Vppon my sword. {D4v}1.5.147

View Commentary Note for 850
850 Ham. Neuer to speake of this that you haue seene1.5.153

View Material Textual Note for 850
850 Ham. Neuer to speake of this that you haue seene1.5.153

View Commentary Note for 851
851 Sweare by my sword.1.5.154

View Immaterial Textual Note for 851
851 Sweare by my sword.1.5.154

View Material Textual Note for 851
851 Sweare by my sword.1.5.154

View Material Textual Note for 853
853 Ham. Hic, & vbique, then weele shift {our} <for> ground:1.5.156

View Commentary Note for 857
857 {Sweare by my sword}1.5.159

View Commentary Note for 858
858 Ghost. Sweare {by his sword}.1.5.161