Genesis 50:3

And forty days were fulfilled for him; for so are fulfilled the days of those which are embalmed: and the Egyptians mourned for him threescore and ten days.

Forty days were fulfilled for him. Diodorus says, generally 'upwards of thirty days were allotted for the completion of the process.'

The Egyptians mourned for him threescore and ten days. This included the whole period of embalming. Both 70 and 72 days are mentioned as the full number, the first being ten weeks of seven days, or seven decades; the other, 12 + 6 = 72, the duodecimal calculation being also used in Egypt. The manner of their mourning was this-`The family mourned at home, singing the funeral dirge, very much as is now done in Egypt; and during this time they abstained from the bath, wine, delicacies of the table, and rich clothing. On the death in any house of a person of consequence, immediately the women plaster their heads, and sometimes even their faces, with mud, and sally forth, wandering through the city, with their dress fastened by a band, and their bosoms bare, beating themselves as they walk. The men, similarly dressed, beat their breasts separately.' In the case of Jacob, it was made a period of public mourning as on the death of a royal personage (Rawlinson's 'Herodotus,' book 2:, chapter 86:; Hengstenberg's 'Egypt and Books of Moses').