Numbers 20:29
And when all the congregation saw that Aaron was dead, they mourned for Aaron thirty days, even all the house of Israel.
Cross-references
Deuteronomy 34:8
Parallel
Deuteronomy 34:8 records the same 30-day mourning period for Moses — directly parallel to Aaron's mourning here.
1 Samuel 25:1
Parallel
1 Samuel 25:1 records all Israel lamenting Samuel's death — a direct parallel to the corporate mourning for Aaron.