Is it true what is narrated in the books of Ahl al-Sunnah that the Prophet Muhammad (peace be upon him) cursed those who lagged behind the army of Usama, and that Abu Bakr and Umar lagged behind this army?

This ḥadīth is fabricated and forged by the consensus of those knowledgeable (in ḥadīth), for the Prophet (peace and blessings be upon him) did not say: "May Allah curse whoever lags behind him." Nor does this ḥadīth have a sound chain of narration in the books of the people of ḥadīth. None of Usamah's companions lagged behind in going out with him; rather, Usamah himself hesitated to depart out of concern for the Prophet (peace and blessings be upon him), whereupon the Prophet permitted him to stay. All of them did go out with him after the Prophet's (peace and blessings be upon him) passing. Abu Bakr was not part of Usamah's army; rather, he sought Usamah's permission to stay because he needed him, and Usamah granted it. Abu Bakr was the most zealous person in preparing Usamah's army after the Prophet's (peace and blessings be upon him) passing.