Musannaf Ibn Abi Shayba 1:829

Abu al-Ahwas narrated to us, from Abu Ishaq, from Abd al-Rahman ibn al-Aswad, who said: Al-Aswad would be in a state of major ritual impurity (janaba), so he would perform ghusl (ritual bath). Then he would come to his wife and lie beside her to warm himself by her before she had performed ghusl.