Found the following hamletworks.org entries referring to line 2811-2

View Commentary Note for 2811-14
2811-2 King. Follow her close, | giue her good watch I pray you. 
2813-4 O this is the poyson of deepe griefe, it springs | all from her Fathers 
2814 death, {and now behold,} ô Gertrard, Gertrard,4.5.77

View Immaterial Textual Note for 2811-14
2811-2 King. Follow her close, | giue her good watch I pray you. 
2813-4 O this is the poyson of deepe griefe, it springs | all from her Fathers 
2814 death, {and now behold,} ô Gertrard, Gertrard,4.5.77

View Material Textual Note for 2811-14
2811-2 King. Follow her close, | giue her good watch I pray you. 
2813-4 O this is the poyson of deepe griefe, it springs | all from her Fathers 
2814 death, {and now behold,} ô Gertrard, Gertrard,4.5.77