Five rabbis, still in prison garb after serving time for demonstrating too close to the Soviet Embassy, renewed their protests yesterday on the way home from jail.

Gathering at the gate of the embassy, they read aloud a letter addressed to Soviet Secretary-General Mikhail Gorbachev and were told by a voice from an intercom that it should be mailed because it would not be accepted at the door.

The letter said in part: "We will not rest until every Jew in the Soviet Union is allowed to flee your vicious persecution. The horrible lesson we learned from Nazi Germany (at whose hands your country suffered greatly) is that we can not afford to be silent."

The rabbis, released yesterday from the federal prison in Petersburg, Va., after serving 12-day sentences, again were within the 500-foot radius that is supposed to be demonstration-free, but police made no attempt to arrest them this time.

The rabbis said daily 15-minute vigils at the embassy will continue, and that more acts of civil disobedience might be carried out next month.

The five rabbis were imprisoned Dec. 13 after choosing not to pay $50 fines assessed by a D.C. Superior Court judge for demonstrating too close to an embassy