Rav Zelig Reuvein Bengis Rabbi of Yerushalaim told over the following story.
Rav Chaim Volozhiner had a personal custom that he was particular to make a Berocho only if someone was nearby to answer Amen. This is based on a Zohar.
Once very late at night after midnight he was very thirsty but everyone in his home was sleeping and there was no one to answer Amen to his Berocho.
Suddenly there was a knock on his door. A boy from the Yeshiva walked in and asked the Rosh Yeshiva a question that was bothering him. The Rosh Yeshiva asked the boy to answer Amen to his Berocho of Shehakol and Borei Nefashos, and then went on to explain the answer to the boy. He was so grateful to the boy that he was able to have a drink.
The next morning when he came to Yeshiva he met the boy and again thanked him for answering Amen and enabling him to drink. The boy looked at the Rosh Yeshiva and didn’t know what he was talking about. He explained that he never came to the Rosh Yeshiva last night. It seems that from Heaven a Malaach was sent to allow him to drink.
