understand - Greek, “know.” The Philippians probably had feared that his imprisonment would hinder the spread of the Gospel; he therefore removes this fear.
the things which happened unto me - Greek, “the things concerning me.”
rather - so far is my imprisonment from hindering the Gospel. Faith takes in a favorable light even what seems adverse [Bengel] (Phi 1:19, Phi 1:28; Phi 2:17).