Muwatta Imam Malik Book of Hajj, Hadith 67

Yahya related to me from Malik that Sumayy, the mawla of Abu Bakr ibn Abd ar-Rahman, heard Abu Bakribn Abd ar-Rahman say, "A woman came to the Messenger of Allah ﷺ and said, 'I had arranged to do hajj, but I was prevented,' and the Messenger of Allah ﷺ said, 'Do umra in Ramadan, for doing umra in it is like doing hajj.' "

وَحَدَّثَنِي عَنْ مَالِكٍ، عَنْ سُمَىٍّ، مَوْلَى أَبِي بَكْرِ بْنِ عَبْدِ الرَّحْمَنِ أَنَّهُ سَمِعَ أَبَا بَكْرِ بْنَ عَبْدِ الرَّحْمَنِ، يَقُولُ جَاءَتِ امْرَأَةٌ إِلَى رَسُولِ اللَّهِ ﷺ فَقَالَتْ إِنِّي قَدْ كُنْتُ تَجَهَّزْتُ لِلْحَجِّ فَاعْتَرَضَ لِي . فَقَالَ لَهَا رَسُولُ اللَّهِ ﷺ " اعْتَمِرِي فِي رَمَضَانَ فَإِنَّ عُمْرَةً فِيهِ كَحِجَّةٍ " .