Revised Standard Version here follows the word order of the Greek text, which Good News Translation has somewhat rearranged for the sake of English style. Compare the two.

Lord is the same noun of address used in verses 2 and 6. As in Matthew 8.6, the polite form of address is to be preferred.

I am not worthy can be expressed as “I am not good enough,” “I am not important enough,” or, as in Good News Translation, “I don’t deserve.” It may also be possible to say “you are too important to come into my house.”

Under my roof represents an idiomatic expression which Good News Translation translates “into my house.” Many languages will have their own idiomatic ways of saying this same thing.

But only say the word: in the context word clearly means an order; New American Bible says “Just give an order”; Good News Translation “Just give the order.” Other ways can be “Just say it shall be done” or “Just say for him to be healed.”

The servant will be healed, that is, “he will become well” or “he will be well again.”

Some ancient manuscripts omit the words my servant from the text, but translationally some subject must be given for the verb. In Greek, of course, the third person (“he” or “she”) is automatically indicated by the verb ending. However, for English speakers either a noun or a pronoun must be included.

Quoted with permission from Newman, Barclay M. and Stine, Philip C. A Handbook on the Gospel of Matthew. (UBS Handbook Series). New York: UBS, 1988. For this and other handbooks for translators see here .