Some of the wives of the Prophet ﷺ asked him, "Which of us will be the first to join you?"He replied, "The one with the longest hand among you."So they took a reed and began measuring their hands with it, and Sawda turned out to have the longest hand. Later we came to understand that the length of her hand referred to her charity, and she was indeed the first of us to join him, for she loved giving charity.
إن بعض أزواج النبي ﷺ قلن للنبي ﷺ: أينا أسرع بك لحوقا؟ قال: أطولكن يدا، فأخذوا قصبة يذرعونها، فكانت سودة أطولهن يدا، فعلمنا بعد أنما كانت طول يدها الصدقة، وكانت أسرعنا لحوقا به، وكانت تحب الصدقة.
Bukhari narrated it in the Book of Zakat (1420) from Musa bin Ismail, who said, Abu Awana narrated to us, from Firas, from Shaybi, from Masruq, from Ayesha, who said, and she related it.Ahmad (24899), Nasai (2541), and Ibn Hibban (3315) all narrated it likewise, through the route of Abu Awana with his chain, and they added that she was Sawda, because she had the longest reach among them. Bukhari did not mention Sawda's name, either because it was not transmitted to him, or because he recognized the error in mentioning Sawda, the mistake in it being from Abu Awana. Others besides him narrated from Firas, with his chain, that she was Zaynab.This makes Ayesha's statement coherent, "We later realized that what was meant by the length of her reach was charity, and Zaynab was the quickest of us to join him, for she loved charity and worked with her own hands." Zaynab died in the year 20 AH, while Sawda died in the year 23 AH.Perhaps Bukhari left out the mention of Sawda bint Zama because of this disagreement. So if the more correct view is that she was Zaynab bint Jahsh, then the mention of Sawda in the narration of Abu Awana is shadh (anomalous).