Found the following hamletworks.org entries referring to line 842

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

View Immaterial Textual Note for 842
842 Ham. Vppon my sword. {D4v}  

View Material Textual Note for 842
842 Ham. Vppon my sword. {D4v}  

View Commentary Note for 843
843 Mar. We haue sworne my Lord already.1.5.147

View Commentary Note for 848
848 Consent to sweare.1.5.152

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