This short post explains why, according to many traditions, the first stanza of "Shalom Aleichem" addresses the "ministering angels" ("malachei hasharet") while the rest of them address the "angels of peace" ("malachei hashalom"). This response by journalist Dovid Zaklikowski was posted on Chabad.org, the website of the Chabad-Lubavitch Hasidic movement.
Question:
In the first stanza of the Shalom Aleichem hymn that we sing on Friday night before the Shabbat meal, we wish peace upon the malachei hasharet, "ministering angels." In the following three stanzas we address malachei hashalom "angels of peace." What is the significance of the variation in the description employed?
Answer:
Let us start with an aggadaic section of the Talmud:
Rabbi Jose the son of Judah said, two ministering angels — one good angel, and one "evil" (prosecuting) angel — accompany a person home on Friday night from the synagogue.
When they arrive home, if they find a candle lit, the table set, and beds arranged nicely, the good angel says, "May it be G‑d's will that next Shabbat be the same," and the evil angel is compelled to respond, "Amen!"
Otherwise, [if the home is not prepared in honor of Shabbat,] the evil angel says, "May it be G‑d's will that next Shabbat be the same," and the good angel is compelled to respond, "Amen!"
The first stanza of the Shalom Aleichem wishes peace to all the ministering angels; the two which are present as well as all the others who are not.
We then specifically address the two angels who are present. They are dubbed "angels of peace," because (hopefully) upon seeing the beautifully set Shabbat table and candles, the good one has proclaimed his blessing, wishing that this beautiful Shabbat aura repeat itself next week, and the bad angel says, "Amen!" They have thus made peace.
We welcome, request blessing from, and then respectfully bid farewell to these two angels who have graced our home with their holy presence.
Although it seems strange to bid farewell to the angels so quickly — why not invite them to join the Shabbat meal? — Rabbi Yosef Yitzchak of Lubavitch explained that it is in bad taste to eat while others who are not eating (or in this case, cannot eat) are watching.