 The exact reason remained unknown, but various scholars including Muslims and non-Muslims argue that Khalid's dismissal from army at zenith of his power was due to the fact that muslims started having faith in Khalid's command rather than God for being victorious which worried Umar, who saw this as a threat to religious believes of Muslims which says only to rely on God.Also a poet wrote some poetry on Khalid's bravery and Khalid being impressed, gave him some award.When Umer learned about it, he called Khalid and said,
Khalid, on his return from an expedition of Amida and Edessa was charged for embezzlement and thus was dismissed from army.