automatos describes an event occurring without external action, as an opening gate or fruit-bearing earth.

The two occurrences depict something happening without an indicated external agent: the earth bears fruit in Mark 4:28, and an iron gate opens in Acts 12:10.

1. Occurring without external action · dominant

   The nominative singular feminine form is used of the earth as it bears fruit in Mark 4:28 and of the iron gate as it opens in Acts 12:10. In Mark 4:28 the APB renders the clause “By itself the earth bears fruit”; in Acts 12:10 it renders the gate’s opening “by itself.”

   Mark 4:28Acts 12:10

In the Anselm Project Bible: Across both verses, the APB explicitly uses “by itself,” applying it to the earth’s fruit-bearing in Mark 4:28 and the iron gate’s opening in Acts 12:10. The verse is read as a whole, but both clauses present the same absence of an indicated external action.