Musnad Ahmad 30:775

Marwan ibn Mu'awiyah al-Fazari narrated to us, Yazid ibn Kaysan informed us: I sought permission to enter upon Salim ibn Abi al-Ja'd while he was praying, so he glorified Allah (said "SubhanAllah") for me. When he finished the prayer, he said: "The permission for a man, if he is in prayer, is to glorify Allah (say 'SubhanAllah'), and the permission for a woman is to clap."