Shaykh al-Albani observed, “Whoever surveys the hadith corpus will realize that the option mentioned was granted only at the outset of the Prophet’s pilgrimage ﷺ. Thereafter the matter did not remain open; rather, he forbade every pilgrim who had not driven a sacrificial animal—whether performing ifrad (solitary Hajj) or qiran (combined Hajj and ʿUmrah)—from leaving his pilgrimage as it was, and ordered him to convert it into an ʿUmrah. He then made this a lasting ruling until the Day of Resurrection.
Imam Ahmad and the hadith scholars, however, do not deem the dissolution obligatory; they regard it as recommended. They interpret the Prophet’s sternness and anger over the issue as a reaction to the Companions’ slowness to obey him, intended to eradicate the pre-Islamic custom of avoiding ʿUmrah during the months of Hajj. The approach of Imam Ahmad and his followers is therefore a commendable middle path between the competing views. Allah knows best."