As-salamu alaikum wa Rahmatullahi wa Barakatoh,
The narrator says that during his youth, he along with his father had a meal with Imām Rezā (alayhi salām) on the night of 25th Zilqad
Imām Alī ibn Mūsā al-Rezā (alayhi salām) said:
“Ibrahim (alayhi salām) and Isa bin Maryam (alayhi salām) were born on 25th Zilqad, earth was spread under the Holy Kaaba in this night only and one who fasts on this day will get the reward of fasting for sixty years.”
[Reference: Sawabul Aamaal, Pg. 116]