Man Lā Yaḥḍuruh al-Faqīh #722"The reward for Hajj is Paradise, and Umrah is an expiation for all sins. The best Umrah is the Umrah performed in the month of Rajab."
Man Lā Yaḥḍuruh al-Faqīh #1399"There is an Umrah for every month."
I asked him: "Can it be less than that?"
Imam (as) said: "There is an Umrah for every ten days."