"on message" meaning in Middle English

{
  "head_templates": [
    {
      "args": {
        "1": "enm",
        "2": "prepositional phrase"
      },
      "expansion": "on message",
      "name": "head"
    }
  ],
  "lang": "Middle English",
  "lang_code": "enm",
  "pos": "prep_phrase",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Middle English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with 2 entries",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        }
      ],
      "examples": [
        {
          "ref": "1485, Sir Thomas Malory, chapter I, in Le Morte Darthur, book II (in Middle English):",
          "text": "So whan the kynge was come thyder with all his baronage and lodged as they semed best / ther was come a damoisel the whiche was sente on message from the grete lady lylle of auelyon / And whan she came bifore kynge Arthur / she told from whome she came / and how she was sent on message vnto hym for these causes",
          "type": "quote"
        }
      ],
      "glosses": [
        "on an errand"
      ],
      "id": "en-on_message-enm-prep_phrase-4AQJlZ~W",
      "links": [
        [
          "errand",
          "errand"
        ]
      ]
    }
  ],
  "word": "on message"
}

{
  "head_templates": [
    {
      "args": {
        "1": "enm",
        "2": "prepositional phrase"
      },
      "expansion": "on message",
      "name": "head"
    }
  ],
  "lang": "Middle English",
  "lang_code": "enm",
  "pos": "prep_phrase",
  "senses": [
    {
      "categories": [
        "Middle English entries with incorrect language header",
        "Middle English lemmas",
        "Middle English multiword terms",
        "Middle English prepositional phrases",
        "Middle English terms with quotations",
        "Pages with 2 entries",
        "Pages with entries",
        "Requests for translations of Middle English quotations"
      ],
      "examples": [
        {
          "ref": "1485, Sir Thomas Malory, chapter I, in Le Morte Darthur, book II (in Middle English):",
          "text": "So whan the kynge was come thyder with all his baronage and lodged as they semed best / ther was come a damoisel the whiche was sente on message from the grete lady lylle of auelyon / And whan she came bifore kynge Arthur / she told from whome she came / and how she was sent on message vnto hym for these causes",
          "type": "quote"
        }
      ],
      "glosses": [
        "on an errand"
      ],
      "links": [
        [
          "errand",
          "errand"
        ]
      ]
    }
  ],
  "word": "on message"
}