Who is Rabbi Eliahu, and why does Eliezer pray he will not do to his own father what Rabbi Eliahu’s son has done to his

in 2 sentence

Rabbi Eliahu is a fellow prisoner in the concentration camp who is desperately searching for his son. Eliezer prays that he will not abandon his father like Rabbi Eliahu's son did, as he witnesses the devastating separation and loss that Rabbi Eliahu experiences.