Musannaf Ibn Abi Shayba 3:3149

'Abd al-Wahhab narrated to us, he said: I asked Yunus about a man who is attending to his mother, or his father, or his relative; does he have an excuse to leave the Friday prayer? He said: Al-Hasan used to grant a concession regarding it for the person in charge of a funeral if he fears for it, or for a man who is afraid.