Greek Study Matthew 10:40-42
v40 ο δεχομενος (δεχομαι) "he who receives" - or better, "the one welcoming as a guest" = It was expected that a person's agent would be received as if it were they who were making the approach. To not welcome the agent is to not welcome the one who sent them.
υμας pro. "you" referring to the apostles and their mission.
τον αποστειλαντα (αποστελλω) aor. part. "the one who sent [me]" participle serves as a substantive- the Father is the intended sender.
v41 ο δεχομενος (δεχομαι) pres. mid. part. "whoever welcomes".
προφητην (ης) "a prophet" - In a general sense, one who declares the word of God, although for Jews of the first century the word would probably only apply to a person who declared a direct word from God, a "thus says the Lord" word.
εις ονομα "because he is" – literally to the name - a semitism meaning "in view of his being "; The sense is of welcoming a person who is a prophet because we know he is a prophet, rather than welcoming him just because he is just a visitor.
προφητου (ης ου) gen. "a prophet's" μισθον (ος) "reward" – idiom = wages. The person who welcomes a prophet receives "the pay" of a prophet. likely the one who welcomes "receives the reward that the messenger of God gives."
δικαιου gen. adj. "a righteous man's / person's [reward]" - of a righteous person. The adjective serves as a substantive, while the genitive is adjectival, attributive, as "prophet's reward" above. Possibly in a general sense, "A good man". Also possibly referring to a class of religious scholars, teachers etc. who functioned in Jewish society. The allusion, of course, is to the disciples
v42 ο αν + subj. "if anyone" - a relative conditional clause, 3rd class, where the stated condition has the possibility of coming true.
ποτιση (ποτιζω) aor. subj. "gives" – in a dry clime most insignificant gift that one person can give to another is a cup of water.
ψυχρου gen. adj "of cold water" – i.e. spring water, deep well water. Even today in the middle east, adding ice to cool water is considered a luxury.
μικρων (ος) gen. adj. "[one] of [these] little ones" - little, small. The adjective serves as a substantive, carrying the sense "insignificant ones" i.e. the socially and political marginal.
εις ονομα "to the name" - See v41.
αμην λεγω υμιν "truly I tell you" - Serving to underline the following statement.
ου μη + subj. "[that person will] certainly not [lose]" - This construction, a subjunctive of emphatic negation, serves to emphasize the fact that the reward will in no way be removed.
αυτου gen. pro. "their [reward]" Possessive genitive.