Have sealed to them - That is, have “secured it” to them. To seal an instrument of writing, a contract, deed, etc. is to “authenticate it,” to make it “sure.” In this sense it is used here. Paul was going himself to see that it was placed “securely” in their hands.
This fruit - This result of the liberality of the Gentile churches - the fruit which their benevolence had produced.
I will come ... - This was Paul’s full purpose; but it is not clear that he ever accomplished it; Note, Romans 15:24.
By you - Taking Rome in my way.