JERUSALEM — An Israeli soldier who fatally shot a Palestinian assailant who was already severely wounded and lying on the ground was released on Tuesday after serving nine months in prison, closing a case that polarized Israelis and thrust the military, a revered institution in Israel, into the heart of an anguished public debate.

The soldier, Elor Azaria, a sergeant before he was demoted, was convicted of manslaughter last year and sentenced to 18 months in prison for killing Abdel Fattah al-Sharif in March 2016 in Hebron, in the West Bank. The military reduced Mr. Azaria’s sentence to 14 months, citing compassion and consideration for his combat service; he ended up serving about two-thirds of his term before being paroled.

Some right-wing ministers welcomed the homecoming of Mr. Azaria, who has expressed no remorse for his act.

Mr. Sharif, 21, and another man had stabbed an Israeli soldier at a Hebron checkpoint and had been shot.