It is narrated from Sayyidah Aishah (may Allah be pleased with her) that the Messenger of Allah (peace and blessings be upon him) said to his wives: "The first of you to join me will be the one with the longest hand." Sayyidah Aishah (may Allah be pleased with her) said: So whenever we gathered after the death of the Messenger of Allah (peace and blessings be upon him), we would stretch our hands against the wall to measure their length. We kept doing that until Sayyidah Zaynab bint Jahsh bin Ri'ab (may Allah be pleased with her) passed away. She was short in stature and was not the one with the longest hand among us, so we realised that by the length of the hand the Prophet (peace and blessings be upon him) meant charity. She was a skilled woman who worked with her hands and gave its proceeds in charity in the path of Allah.
Hadith Referenceالمعجم الكبير للطبراني / مسند النساء / 20504