Musnad Ahmad 1153:122

Sufyan narrated to us, from Ibn Ubayd ibn Nustas—meaning Abu Ya'fur—from Muslim, from Masruq, from Aisha, who mentioned regarding the Prophet, may Allah bless him and grant him peace: "When the ten [days] entered, he would revive the night, awaken his family, and tighten his waist-wrapper." Sufyan said: "And one of them is from the last [ten]."