In the tafsir, https://quran.com/3:172/tafsirs/en-tafsir-maarif-ul-quran, there is a comment which says,

"The first one appears in مِن بَعْدِ مَا أَصَابَهُمُ الْقَرْ‌حُ (even after they had received the wound) which means that those who responded to the call of Allah and His Messenger were people wounded at the Battle of Badr."

I think Battle of Badr is wrongly stated here. It must be Battle of Uhud.