Charles Ellicott Commentary Jeremiah 16:4

"They shall die grievous deaths: they shall not be lamented, neither shall they be buried; they shall be as dung upon the face of the ground; and they shall be consumed by the sword, and by famine; and their dead bodies shall be food for the birds of the heavens, and for the beasts of the earth." — Jeremiah 16:4 (ASV)

Of grievous deaths. —Literally, deaths from diseases, including, perhaps, famine , as contrasted with the more immediate work of the sword.

They shall not be lamented. —Among a people who attached such importance to the due observance of funeral rites as the Jews did, the neglect of those rites was, of course, here, as in Jeremiah 22:18, a symptom of extreme misery. Like features have presented themselves in the pestilences or sieges of other cities and other times, as in the description in Lucretius (vi. 1278):—

“Nec mos ille sepulturæ remanebat in urbe,
Quo pius hic populus semper consuerat humari.”
“No more the customary rites of burial
Were practised in the city, such as was customary
Of old to tend the dead with reverent care.”

Compare the account of the plague at Athens in Thucydides (ii. 52).