How to match fields starting with phrase

Elastic Stack Elasticsearch
1

Say I have an analyzed field, and I want to do a search that matches on that field if the field starts with the supplied phrase. For example, say I have two documents, each with a single field:

doc1 : {
    name: "the dog is happy"
}

doc2: {
    name: "happy the dog is"
}

Say my query string is "the dog is". I want to match doc1 and not doc2. How can I do this?

Thanks!