Muhammad bin Ajlan al-Madni محمد بن عجلان المدني · The Book of al-Bay'ah

"I gave my pledge to the Prophet to hear and obey, and he told me to add the words.' In as much as you can, and to be since toward every Muslim"'. (Sahih) '

"We gave pledge to the Messenger of Allah among a group of women, and he said to us: 'In as much as you can and are able ."'