Hadith Q889
إِذَا كَلَّمَ الْمُصَلِّي وَفِي الْخَبَرِ مَا دَلَّ عَلَى الرُّخْصَةِ فِي إِصْغَاءِ الْمُصَلِّي إِلَى مُكَلِّمِهِ وَاسْتِمَاعِهِ لَكَلَامِهِ فِي الصَّلَاةِ
And in the hadith, there is evidence that a person performing prayer is permitted to listen attentively and carefully to the conversation of someone speaking to him.
Hadith 889
Sayyiduna Jabir (may Allah be pleased with him) narrates that the Messenger of Allah (peace and blessings of Allah be upon him) sent me to Banu Mustaliq (for some task). So I returned to the Messenger of Allah (peace and blessings of Allah be upon him) and he was performing prayer while riding his donkey. I kept talking to him, and he indicated to me with his hand.