The Talmud identifies the four primary angels who minister before God, among them Refael, whose specific function is healing (refu'ah). The name is etymologically linked to רפא — to heal — marking Refael as the angel of healing in rabbinic tradition.
אָמַר רַבִּי אֶלְעָזָר בַּר אֲבִינָא: גָּדוֹל מַה שֶּׁנֶּאֱמַר בְּמִיכָאֵל יוֹתֵר מִמַּה שֶּׁנֶּאֱמַר בְּגַבְרִיאֵל, דְּאִילּוּ בְּמִיכָאֵל כְּתִיב: ״וַיָּעׇף אֵלַי אֶחָד מִן הַשְּׂרָפִים״. וְאִילּוּ גַּבֵּי גַבְרִיאֵל כְּתִיב: ״וְהָאִישׁ גַּבְרִיאֵל אֲשֶׁר רָאִיתִי בֶחָזוֹן בַּתְּחִלָּה מֻעָף בִּיעָף וְגוֹ׳״. מַאי מַשְׁמַע דְּהַאי ״אֶחָד״ מִיכָאֵל הוּא? אָמַר רַבִּי יוֹחָנָן: אַתְיָא ״אֶחָד״ ״אֶחָד״. כְּתִיב הָכָא ״וַיָּעׇף אֵלַי אֶחָד מִן הַשְּׂרָפִים״, וּכְתִיב הָתָם: ״וְהִנֵּה מִיכָאֵל אֶחָד (מִן) הַשָּׂרִים הָרִאשׁוֹנִים בָּא לְעָזְרֵנִי״. תָּנָא: מִיכָאֵל — בְּאַחַת, גַּבְרִיאֵל — בִּשְׁתַּיִם, אֵלִיָּהוּ — בְּאַרְבַּע, וּמַלְאַךְ הַמָּוֶת — בִּשְׁמֹנֶה. וּבִשְׁעַת הַמַּגֵּפָה, בְּאֶחָת.
After this discussion of the statement that Rabbi Elazar said that Rabbi Avina said, another statement of Rabbi Elazar is cited. Rabbi Elazar bar Avina said: What was said about the angel Michael is greater than what was said about the angel Gabriel. As about Michael, it is written: “And one of the seraphim flew to me” (Isaiah 6:6), indicating that with a single flight, the seraph arrived and performed his mission, while regarding Gabriel, it is written: “The man, Gabriel, whom I had seen at the beginning, in a vision, being caused to fly swiftly, approached close to me about the time of the evening offering” (Daniel 9:21). The double language used in the phrase “to fly swiftly [muaf biaf],” indicates that he did not arrive at his destination in a single flight, but rather, that it took him two flights. To Rabbi Elazar bar Avina, it is clear that “one of the seraphim” refers to Michael, and the Gemara asks: From where is it inferred that the one mentioned in the verse is Michael? Rabbi Yoḥanan said: This is derived through a verbal analogy between the words one and one. Here, it is written: “And one of the seraphim flew to me” (Isaiah 6:6), and there, it is written: “And behold, Michael, one of the chief ministers of the king, came to my aid” (Daniel 10:13). Since the verse from Daniel refers to Michael as “one,” which aggadic midrash interprets as “the unique one,” so, too, “one of the seraphs” described in Isaiah must also refer to the unique one, Michael. This discussion in the Gemara concludes with a Tosefta that arrives at a hierarchy of angels based on the number of flights required by each to arrive at his destination. It was taught in a Tosefta: Michael, as stated above, in one flight; Gabriel, in two flights; Elijah the Prophet, in four flights; and the Angel of Death, in eight flights. During a time of plague, however, when the Angel of Death seems ubiquitous, he arrives everywhere in one flight.