Adam Clarke on Psalms 89:45

The days of his youth hast thou shortened - Our kings have not reigned half their days, nor lived out half their lives. The four last kings of Judea reigned but a short time, and either died by the sword or in captivity.

Jehoahaz reigned only three months, and was led captive to Egypt, where he died. Jehoiakim reigned only eleven years, and was tributary to the Chaldeans, who pat him to death, and cast his body into the common sewer. Jehoiachin reigned three months and ten days, and was led captive to Babylon, where he continued in prison to the time of Evilmerodach, who, though he loosed him from prison, never invested him with any power. Zedekiah, the last of all, had reigned only eleven years when he was taken, his eyes put out, was loaded with chains, and thus carried to Babylon. Most of these kings died a violent and premature death. Thus the days of their youth - of their power, dignity, and iife, were shortened, and they themselves covered with shame. Selah; so it most incontestably is.