A.T. Robertson Commentary Romans 15:29

"And I know that, when I come unto you, I shall come in the fulness of the blessing of Christ." — Romans 15:29 (ASV)

When I come (ερχομενος). Present middle participle of ερχομα with the time of the future middle indicative ελευσομα (coming I shall come).

In the fulness of the blessing of Christ (εν πληρωματ ευλογιας Χριστου). On πληρωματ, see 11:12. Paul had already (1:11f.) said that he had a χαρισμα πνευματικον (spiritual blessing) for Rome. He did bring that to them.