Ibn Abbas reported: The Messenger of 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 so-and-so 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
Grade: Sahih (authentic) according to Al-Bukhari
عن ابن عباس رَضِيَ اللَّهُ عَنْهُمَا قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ لِامْرَأَةٍ مِنْ الْأَنْصَارِ سَمَّاهَا ابْنُ عَبَّاسٍ فَنَسِيتُ اسْمَهَا مَا مَنَعَكِ أَنْ تَحُجِّينَ مَعَنَا قَالَتْ كَانَ لَنَا نَاضِحٌ فَرَكِبَهُ أَبُو فُلَانٍ وَابْنُهُ لِزَوْجِهَا وَابْنِهَا وَتَرَكَ نَاضِحًا نَنْضَحُ عَلَيْهِ قَالَ فَإِذَا كَانَ رَمَضَانُ اعْتَمِرِي فِيهِ فَإِنَّ عُمْرَةً فِي رَمَضَانَ حَجَّةٌ
1690 صحيح البخاري كِتَاب الْعُمْرَةِ بَاب عُمْرَةٍ فِي رَمَضَانَ