It is narrated from Urwah who reports that Aisha (may Allah be pleased with her) said to me: "When you perform Hajj, do you make an exception (istithna)?" Urwah says: I asked, "What should I say?" Aisha (may Allah be pleased with her) said: Say, 'O Allah, I have intended Hajj and set out for it. If You make it easy for me, then it is Hajj, and if any obstacle prevents me, then it is Umrah.'"
Hadith Referenceمسند الإمام الشافعي / كتاب الحج / 813
Hadith Takhrijاسناده صحیح اخرجه البيهقى 5 / 223 ۔ وفى المعرفة السنن والآثار له (3262)۔