Adam Clarke on Acts 9:21

Is not this he that destroyed them - Ὁ πορθησας. The verb πορθειν has three acceptations in the Greek writers:

1. To treat one as an enemy, to spoil him of his goods.

2. To lead away captive, to imprison.

3. To slay.

Paul was properly πορθων, a destroyer, in all these senses.

1. He acted as the most determined enemy of the Christians: Being exceedingly mad against them, he persecuted them to strange cities, Act 26:11.

2. He shut up many of the saints in prison, Act 8:3; Act 9:14; Act 26:10.

3. He persecuted them unto death - gave his voice against them that they might be destroyed, and was a principal instrument in the martyrdom of Stephen. He breathed threatenings and slaughter. See Act 7:58; Act 8:1; Act 9:1; Act 26:10, Act 26:11.

Therefore these three meanings of the original word are all exemplified in the conduct of Saul.