Mukhtasar Muslim

Tawoos says: We said to Sayyiduna Ibn Abbas (may Allah be pleased with them), "What do you say about the sitting posture of Iq’aa?" He said, "It is Sunnah." We said, "We consider this sitting to be hard on a person (or on the feet)." He said, "(No), rather it is the Sunnah of your Noble Prophet (peace and blessings be upon him)." (Iq’aa is to sit with both feet upright and sitting on the heels.)