What is the authenticity of the historical narration which states that the Ansar offered the Muhajirun that they divorce one of their wives so that the Muhajirun could marry her, and did Al-Albani authenticate this narration?

The story mentioned is a wonderful example of the generosity of the Ansar and their solidarity with the Muhajireen. The Prophet, peace and blessings be upon him, established brotherhood between Abd al-Rahman ibn Awf and Sa'd ibn al-Rabi'. Sa'd offered to divide his wealth and possessions with Abd al-Rahman, but Abd al-Rahman refused and instead married a woman from the Ansar and gave a wedding feast, even if only with one sheep. The presence of this story in Sahih al-Bukhari is strong evidence of its authenticity, and Sheikh Al-Albani also authenticated it.