Note 2 at Acts 13:47: There is no clear reference in scripture where the Lord spoke these words to Paul. The Lord did speak through Ananias to Paul about a ministry to the Gentiles (see note 7 at Acts 9:17, p. 624) and the Lord spoke directly to Paul about being sent to the Gentiles when Paul was in a trance in the temple at Jerusalem (Acts 22:17-21). However, this is not what Paul is referring to.

Paul was not the light to the Gentiles and the salvation for the ends of the earth. Jesus was. This is a quotation from Isa. 49:6. Therefore, this is an example of the Lord speaking to Paul through His Word. When we receive revelation from God's Word, that is God speaking to us. It is a more trustworthy method of hearing God speak than an audible voice (2 Pet. 1:18-20) and it carries a greater blessing (see note 4 at Jn. 20:29, p. 557).