The Prophet (peace be upon him) then told her:
“When the month of Ramadan arrives, go for ‘Umrah, because Umrah in Ramadan is like accompanying me on Hajj.” - [Sahîh al-Bukhârî (1764)] The meaning of this hadith : What a great achievement it would be for one of us to accompany Allah’s Messenger (peace be upon him) on Hajj! Think of standing beside him on the Plain of `Arafah. Imagine spending the night in his encampment in Muzdalifah and then getting up the next morning to go with him to Minâ. What would it be like to perform tawâf and sa`y alongside him.
The apparent meaning of the hadîth is that our performing `Umrah in Ramadan is really that significant.
The month of Ramadan is that in which the Quran was revealed, a guidance to men and clear proofs of the guidance and the distinction; therefore whoever of you is present in the month, he shall fast therein ..." (Albaqara 185)
The Messenger of Allah (peace be upon him) told his companions on the last day of Shaaban: “O people! A great month has come to you; it is a blessed month in which there is a night (Lailat Al-Qadr) that is better than a thousand months; Whoever tries to attain the pleasure of God by performing any of the optional deeds shall receive the same reward of performing an obligatory one in other days, and whoever performs an obligatory deed shall receive the reward of performing 70 obligations.”
The Prophet (peace be upon him) added: “It is the month of patience, and the reward of patience is Heaven. It is the month of charity, and a month in which a believer's sustenance is increased. Whoever gives food to a fasting person to break his fast, shall have his sins forgiven, and he will be saved from the Hell, and he will get the same reward of that fasting person, without lessening the latter’s reward.”
Narrated Ata (Radi-Allahu 'anhu): I heard Ibn 'Abbas saying, "Allah's Apostle (Sallallahu 'Alaihi Wa Sallam) asked an Ansari woman (Ibn 'Abbas named her but Ata forgot her name), 'What prevented you from performing Hajj with us?' She replied, 'We have a camel and the father of so-and-so and his son (i.e. her husband and her son) rode it and left one camel for us to use for irrigation.' He said (to her), 'Perform 'Umra when Ramadan comes, for 'Umra in Ramadan is equal to Hajj (in reward),' or said something similar." Bukhari Vol. 3 : No. 10