Question
who are two biblical personalities who were involved actively in fulfilling the same interpersonal (ben adam lechavero) mitzvah?
Answer
Avraham & Yitzchak both had similar situations where they had to Pray for their wives since they were Akaros, barren. Another instance is Elisha and the widow (Melachim Beis 4:1-7) and Eliyah and the widow (Melachim Alef 17:18).
Hatzlacha,
Rabbi Kermaier