What is the story of Abu Bakr Al-Siddiq's pilgrimage - may Allah be pleased with him - which took place one year before the Farewell Pilgrimage, and what was the covenant that was violated during it?

The Prophet, peace and blessings be upon him, appointed Abu Bakr Al-Siddiq, may Allah be pleased with him, as the leader of the pilgrims in the ninth year [of the Hijra], to announce to the people that no polytheist should perform Hajj, nor should anyone circumambulate the Kaaba naked after that year. The covenants with the polytheists were revoked after the Prophet's departure to Tabuk, because they had breached their agreements. Surah (definition) Bara'ah (Repentance) was revealed, commanding the revocation of the covenants of those who had broken them. The Prophet, peace and blessings be upon him, sent Ali ibn Abi Talib, may Allah be pleased with him, to convey Surah Bara'ah, because it was the custom of the Arabs that the one who had made the covenant, or a man from his tribe, should be the one to revoke it. Surah Bara'ah divided the polytheists into three categories: those who had broken the covenant, and it was commanded to fight them; those who had a temporary covenant which they had not broken, and it was commanded to fulfill their covenant; and those who had no covenant or an unrestricted covenant, and it was commanded to grant them a four-month delay before fighting them.