"And a man found him" (Genesis 37:15-17). Three angels presented themselves to him: "and a man found him," "and the man asked him," "and the man said." "Dothaynah [toward Dothan]" hints at the attributes [middot] of the Holy One, blessed be He. "And a man found him": this is the angel Gabriel, as it is said, "and the man Gabriel, whom [I had seen in the vision at the first,] flying swiftly" (Daniel 9:21).
The Angel Gabriel Meets Joseph on the Road to Dothan
Yalkut Shimoni on Torah 141:4
(בראשית לז טו-יז) וַיִּמְצָאֵהוּ אִישׁ. שְׁלֹשָׁה מַלְאָכִים נִזְדַּמְּנוּ לוֹ "וַיִּמְצָאֵהוּ אִישׁ", "וַיִּשְׁאָלֵהוּ הָאִישׁ", "וַיֹּאמֶר הָאִישׁ". דֹּתָיְנָה, שֶׁהֵן מִדּוֹתָיו שֶׁל הַקָּדוֹשׁ בָּרוּךְ הוּא. וַיִּמְצָאֵהוּ אִישׁ. זֶה גַּבְרִיאֵל הַמַּלְאָךְ, שֶׁנֶאֱמַר (דניאל ט, כא) "וְהָאִישׁ גַּבְרִיאֵל אֲשֶׁר [וְגוֹ'] מֻעָף בִּיעָף".