Or HaChaim on Genesis 32:7/אור החיים על בראשית ל״ב:ז׳

1 וישבו המלאכים, The messengers returned, etc. The meaning is that they brought back a reply and said "we have come to your brother, to Esau, etc." i.e. he presented himself as your brother, whereas in actual fact he has remained Esau. "He is also coming to meet you," i.e. as a brother, but since he has taken four hundred armed men with him this is proof of his evil intentions against you.

2The words "we have come to your brother" may also mean that although he has met us with a happy face i.e. displaying brotherliness, we displayed anger ourselves seeing that he has remained Esau true to form. This is what the Midrash we have quoted meant when it described the messengers as appearing garbed in fiery garments riding on fiery horses. The reason the messengers did not bring back a definitive evaluation was because outwardly Esau displayed brotherliness whereas in his heart he was still the same old Esau, hating Jacob.