The people used to consider performing Amra during the months of Hajj to be one of the gravest sins on earth. They would shift Muharram into Safar, saying, "Once the camels' backs have healed, the tracks of the pilgrims have faded, and Safar has passed, then Amra becomes lawful for whoever wishes to perform it."When the Prophet ﷺ and his companions arrived on the morning of the fourth, having entered the state of ihram for Hajj, he ordered them to convert it into an Amra. This seemed enormous to them, and they asked, "Messenger of Allah, what kind of release is permitted to us?"He replied, "Complete release."In another version it reads, "on the morning."
حدثنا عفان حدثنا وهيب حدثنا عبد الله بن طاوس عن أبيه
كانوا يرون العمرة في أشهر الحج من أفجر الفجور في الأرض ويجعلون المحرم صفرا ويقولون إذا برأ الدبر وعفا الأثر وانسلخ صفر حلت العمرة لمن اعتمر فلما قدم النبي ﷺ وأصحابه لصبيحة رابعة مهلين بالحج فأمرهم أن يجعلوها عمرة فتعاظم ذلك عندهم فقالوا يا رسول الله أي الحل قال الحل كله وفي كتابه لصبح
Its isnad is sahih. Bukhari related it in 3:337-338 from Musa bin Ismail from Wahib, and in 7:112 from Muslim bin Ibrahim Farahidi from Wahib. Muslim related it in 1:355 from Muhammad bin Hatim from Bahz from Wahib."When the dabar healed" - with fatha on the dal and the ba - refers to the sore that forms on a camel's back from carrying loads and the hardship of travel, for it would heal after they returned from Hajj."And the traces were effaced" - Hafiz said in Fath al-Bari, meaning the tracks left by the camels and other animals as they moved were worn away, though it could also refer to the trace of the aforementioned dabar sore. He also said, these words are read with the ra silent, for the sake of the rhymed prose.As for the statement "in his book, al-subh" - it appears to be the words of Abdullah bin Ahmad, saying that he heard from his father "al-subayha rabia" (the fourth morning), but he saw it written in his own hand in his book as "al-subh rabia" (the fourth dawn), whereas the narration of the two Shaykhs has "subayha" without the definite article.See also 2141.