Ibn Abbas reported: Le Messager d'Allah, peace and blessings be upon him, said to an Ansari woman,
“What prevented you from performing the Hajj pilgrimage with us?"
She said, “We have a camel and the father of this man and his son rode it and left only one camel for us to use for irrigation.”
The Prophet said, “Perform the Umrah pilgrimage when Ramadan arrives, for Umrah during Ramadan is equal to the Hajj pilgrimage.”
Source: Sahih Bukhari 1690, Sahih Muslim 1256