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.

Cross-references

Genesis 50:26 records Joseph's own embalming and burial, mirroring the same process and mourning customs for Jacob here.

Numbers 20:29 records a 30-day mourning for Aaron, a shorter period than Jacob's 70 days, but both honor leaders with prescribed mourning.

Deuteronomy 34:8 notes 30 days of weeping for Moses, paralleling the mourning period for Jacob as a great leader.