[Mesorah] "Vayigva Yitzchok vayomos vayeosef el amov"

[SBA]

Parshas Vayishlach - 35:29 "Vayigva Yitzchok vayomos vayeosef el amov" 
(Similarly in Chayei Sarah (25:8) "Vayigva vayomos Avrohom beseiva tova
...vayeosef el amov".

What actually do these 3 separate words for death indicate?

SBA