as to one of untimely birth: This phrase can refer to a miscarriage or stillbirth. Here it might describe the unusual way Paul converted, the negative view some opponents had of his role as an apostle, or his own feelings of unworthiness to be an apostle. The main focus is on God's extraordinary grace to Paul, who once persecuted Christ’s followers (see Galatians 1:13; Philippians 3:6; compare Acts 8:3; 9:1–2).
He appeared to me also: Paul met the risen Christ during his conversion (see 1 Corinthians 9:1; Acts 9:3–6; Galatians 1:15–16).