Why were the executioners taking off their robes? It wasn't just for comfort; it was a solemn, legal requirement.
In Jewish law, witnesses to a crime, especially one punishable by death, were required to be the first to cast stones. This practice, detailed in Deuteronomy 17:7, served as a severe deterrent against false testimony. If you accused someone, you had to be prepared to actively participate in their execution. The witnesses in Stephen's stoning removed their outer garments to avoid hindrance during this grim duty. This detail highlights the perceived legality and solemnity they attached to their actions, even though it was a violent, unlawful mob execution. It also brings Saul directly into the scene, not just as an observer, but as someone responsible for their belongings, placing him firmly within the act itself.