Musannaf Ibn Abi Shaybah

Hazrat Ibn Abbas (may Allah be pleased with both of them) did not consider it objectionable if a thrice-divorced woman or a woman whose husband had passed away performed Hajj during her waiting period (iddah).

It is narrated from Hazrat Ata that Hazrat Aisha (may Allah be pleased with her) made Hazrat Umm Kulthum perform Hajj during her waiting period (iddah).

Hasan says that there is no harm if a woman performs Hajj during her waiting period (iddah).

Hazrat Ata was asked whether a thrice-divorced woman and a woman whose husband has passed away can perform Hajj during their 'iddah. He replied, "Yes." Hazrat Habib states that Hasan also used to say the same.