A.T. Robertson Commentary Mark 10:27

"Jesus looking upon them saith, With men it is impossible, but not with God: for all things are possible with God." — Mark 10:27 (ASV)

Looking on them (εμβλεψας αυτοις). So in Mt 19:26. Their amazement increased (26).

But not with God (αλλ' ου παρα θεω). Locative case with παρα (beside). The impossible by the side of men (παρα ανθρωποις) becomes possible by the side of God. That is the whole point and brushes to one side all petty theories of a gate called needle's eye, etc.