Whenever we pledged allegiance to the Messenger of Allah ﷺ to hear and obey, he would say to us, "In what you are able."
كنا إذا بايعنا رسول الله ﷺ على السمع والطاعة يقول لنا: فيما استطعتم.
Malik narrated it in the Bay'ah (1) from Abdullah bin Dinar, that Abdullah bin Umar mentioned it as he stated. Bukhari narrated it in the Ahkam (7202) via Malik, with the same wording. Muslim narrated it in the Imarah (1867) via Ismail bin Jafar, who said, "Abdullah bin Dinar informed me," with the same wording.