´Sayyiduna Ibn Abbas (may Allah be pleased with them both) says that` in the days of ignorance (that is, before Islam), people considered performing Umrah during the days of Hajj to be the greatest sin on earth, and they used to make the month of Muharram into Safar. } The reason was that three consecutive months are sacred months: Dhu al-Qa'dah, Dhu al-Hijjah, and Muharram. So they would become anxious and could not commit robbery, because even the polytheists of Makkah respected the sacred months. (It is unfortunate that today Muslims do not even know which months are sacred, let alone respect them.) Therefore, they invented this mischief that instead of Muharram, they would write Safar and would commit much robbery, and when the month of Safar came, they would honor it like Muharram. And this was the "Nasi" which Allah Almighty mentions as the habit of the polytheists in the Qur'an. { They used to say that when the backs of the camels become good (that is, the wounds caused by the journey of Hajj have healed), and the tracks of the pilgrims' camels have disappeared from the roads, and the month of Safar is over, then it is permissible for the one performing Umrah to do Umrah. Then, when the Messenger of Allah (peace and blessings be upon him) and his companions entered Makkah in the state of Ihram on the fourth of Dhu al-Hijjah, he (peace and blessings be upon him) commanded them to convert the Ihram of Hajj into Umrah (as is the view of Ibn Qayyim and others). So this seemed very strange to the people, and they said, "O Messenger of Allah (peace and blessings be upon him)! How should we become lawful? (That is, completely or partially, should we still avoid some things?)" So he (peace and blessings be upon him) said, "Become completely lawful (that is, there is no need to avoid anything)."