Al-Matalib al-'Aliyah 2535 — Kindness to parents

It is narrated from al-Awwam bin Hawshab (may Allah have mercy on him) that he asked Imam Mujahid (may Allah have mercy on him), the eminent Successor: "The iqamah for prayer is being called and (at that very moment) my father calls me (what is the ruling in such a case)?" Imam Mujahid (may Allah have mercy on him) said: "Answer your father (and respond to his call)."
Imam Musaddad (may Allah have mercy on him) recorded this athar in his Musnad; it indicates the extraordinary importance of kindness to parents and obeying them, in that answering a father's call, compared with waiting for the congregation or voluntary acts, is a highly commendable act in the Shari'ah.