صحيح البخاري

Narrated Al-Aswad:

That `Aisha said, "O Allah's Messenger! The people are returning after performing the two Nusuks (i.e. Hajj and `Umra) but I am returning with one only?" He said, "Wait till you become clean from your menses and then go to at-Tan`im, assume Ihram (and after performing `Umra) join us at such-andsuch a place. But it (i.e. the reward if `Umra) is according to your expenses or the hardship (which you will undergo while performing it).