They kept on stoning underlines the force of the Greek verb tense. The verb translated called on means “to call on (in prayer).” One might compare this prayer with the prayer of Jesus in Luke 23.46.

Quoted with permission from Newman, Barclay M. and Nida, Eugene A. A Handbook on The Acts of the Apostles. (UBS Handbook Series). New York: UBS, 1972. For this and other handbooks for translators see here .