Khalid ibn al-Walid
The tribe converted and Khalid instructed them in the Qur'an and Islamic laws before returning to Muhammad in Medina with a Balharith delegation.

Commander in the Ridda wars: After Muhammad's death in June 632, one of his early and close companions, Abu Bakr, became caliph (leader of the Muslim community). The issue of succession had caused discord among the Muslims. The Ansar (lit. 'Helpers'), the natives of Medina who hosted Muhammad after his emigration from Mecca, attempted to elect their own leader. Opinion was split among the Muhajirun (lit. 'Emigrants'), the mostly Qurayshite natives of Mecca who emigrated with Muhammad to Medina. One group advocated for a companion closer in kinship to Muhammad, namely his cousin Ali, while another group, backed by new converts among the Qurayshite aristocracy, rallied behind Abu Bakr. The latter, with the key intervention of the prominent Muhajirun, Umar ibn al-Khattab and Abu Ubayda ibn al-Jarrah, overrode the Ansar and acceded. Khalid was a staunch supporter of Abu Bakr's succession. A report preserved in a work by the 13th-century scholar Ibn Abi'l-Hadid claims that Khalid was a partisan of Abu Bakr, opposed Ali's candidacy, and declared that Abu Bakr was "not a man about whom one needs [to] enquire, and his character needs not be sounded out".
Most tribes in Arabia, except those inhabiting the environs of Mecca, Medina and Ta'if discontinued their allegiance to the nascent Muslim state after Muhammad's death or had never established formal relations with Medina. Islamic historiography describes Abu Bakr's efforts to establish or reestablish Islamic rule over the tribes as the Ridda wars (wars against the 'apostates'). Views of the wars by modern historians vary considerably. Watt agrees with the Islamic characterization of the tribal opposition as anti-Islamic in nature, while Julius Wellhausen and C. H. Becker hold the tribes were opposed to the tax obligations to Medina rather than Islam as a religion. In the view of Leone Caetani and Bernard Lewis, the opposing tribes who had established ties with Medina regarded their religious and fiscal obligations as being a personal contract with Muhammad; their attempts to negotiate different terms after his death were rejected by Abu Bakr, who proceeded to launch the campaigns against them.
Of the six main conflict zones in Arabia during the Ridda wars, two were centered in Najd (the central Arabian plateau): the rebellion of the Asad, Tayy and Ghatafan tribes under Tulayha and the rebellion of the Tamim tribe led by Sajah; both leaders claimed to be prophets. After Abu Bakr quashed the threat to Medina by the Ghatafan at the Battle of Dhu al-Qassa, he dispatched Khalid against the rebel tribes in Najd. Khalid was Abu Bakr's third nominee to lead the campaign after his first two choices, Zayd ibn al-Khattab and Abu Hudhayfa ibn Utba, refused the assignment. His forces were drawn from the Muhajirun and the Ansar. Throughout the campaign, Khalid demonstrated considerable operational independence and did not stringently abide by the caliph's directives. In the words of Shaban, "he simply defeated whoever was there to be defeated".

Battle of Buzakha: Khalid's initial focus was the suppression of Tulayha's following. In late 632, he confronted Tulayha's forces at the Battle of Buzakha, which took place at the eponymous well in Asad territory where the tribes were encamped. The Tayy defected to the Muslims before Khalid's troops arrived to Buzakha, the result of mediation between the two sides by the Tayy chief Adi ibn Hatim. The latter had been assigned by Medina as its tax collector over his tribe and its traditional Asad rivals.
Khalid bested the Asad–Ghatafan forces in battle. When Tulayha appeared close to defeat, the Fazara section of the Ghatafan under their chief Uyayna ibn Hisn deserted the field, compelling Tulayha to flee for Syria. His tribe, the Asad, subsequently submitted to Khalid, followed by the hitherto neutral Banu Amir, which had awaited the results of the conflict before giving its allegiance to either side. Uyayna was captured and brought to Medina. As a result of the victory at Buzakha, the Muslims gained control over most of Najd.

Execution of Malik ibn Nuwayra: After Buzakha, Khalid proceeded against the rebel Tamimite chieftain Malik ibn Nuwayra headquartered in al-Butah, in the present-day Qassim region. Malik had been appointed by Muhammad as the collector of the sadaqa ('alms tax') over his clan of the Tamim, the Yarbu, but stopped forwarding this tax to Medina after Muhammad's death. Abu Bakr consequently resolved to have him executed by Khalid. The latter faced divisions within his army regarding this campaign, with the Ansar initially staying behind, citing instructions by Abu Bakr not to campaign further until receiving a direct order by the caliph. Khalid claimed such an order was his prerogative as the commander appointed by the caliph, but he did not force the Ansar to participate and continued his march with troops from the Muhajirun and the Bedouin defectors from Buzakha and its aftermath; the Ansar ultimately rejoined Khalid after internal deliberations.
According to the most common account in the Muslim traditional sources, Khalid's army encountered Malik and eleven of his clansmen from the Yarbu in 632. The Yarbu did not resist, proclaimed their Muslim faith and were escorted to Khalid's camp. Khalid had them all executed over the objection of an Ansarite, who had been among the captors of the tribesmen and argued for the captives' inviolability due to their testaments as Muslims. Afterward, Khalid married Malik's widow Umm Tamim bint al-Minhal. When news of Khalid's actions reached Medina, Umar, who had become Abu Bakr's chief aide, pressed for Khalid to be punished or relieved of command, but Abu Bakr pardoned him.
According to the account of the 8th-century historian Sayf ibn Umar, Malik had also been cooperating with the prophetess Sajah, his kinswoman from the Yarbu, but after they were defeated by rival clans from the Tamim, left her cause and retreated to his camp at al-Butah. There, he was encountered with his small party by the Muslims. The modern historian Wilferd Madelung discounts Sayf's version, asserting that Umar and other Muslims would not have protested Khalid's execution of Malik if the latter had left Islam, while Watt considers accounts about the Tamim during the Ridda in general to be "obscure ... partly because the enemies of Khālid b. al-Walīd have twisted the stories to blacken him". In the view of the modern historian Ella Landau-Tasseron, "the truth behind Malik's career and death will remain buried under a heap of conflicting traditions".

Elimination of Musaylima and conquest of the Yamama: Following a series of setbacks in her conflict with rival Tamim factions, Sajah joined the strongest opponent of the Muslims: Musaylima, the leader of the sedentary Banu Hanifa tribe in the Yamama, the agricultural eastern borderlands of Najd. Musaylima had laid claims to prophet-hood before Muhammad's emigration from Mecca, and his entreaties for Muhammad to mutually recognize his divine revelation were rejected by Muhammad. After Muhammad died, support for Musaylima surged in the Yamama, whose strategic value lay not only with its abundance of wheat fields and date palms, but also its location connecting Medina to the regions of Bahrayn and Oman in eastern Arabia. Abu Bakr had dispatched Shurahbil ibn Hasana and Khalid's cousin Ikrima with an army to reinforce the Muslim governor in the Yamama, Musaylima's tribal kinsman Thumama ibn Uthal. According to the modern historian Meir Jacob Kister, it was likely the threat posed by this army which compelled Musaylima to forge an alliance with Sajah. Ikrima was repelled by Musaylima's forces and thereafter instructed by Abu Bakr to quell rebellions in Oman and Mahra (central southern Arabia) while Shurahbil was to remain in the Yamama in expectation of Khalid's large army.
After his victories against the Bedouin of Najd, Khalid headed to the Yamama with warnings of the Hanifa's military prowess and instructions by Abu Bakr to act severely toward the tribe should he be victorious. The 12th-century historian Ibn Hubaysh al-Asadi holds that the armies of Khalid and Musaylima respectively stood at 4,500 and 4,000. Kister dismisses the much larger figures cited by most of the early Muslim sources as exaggerations.