When we used to pledge allegiance to the Messenger of Allah ﷺ to hear and obey, he would say to us, "In what you are able to do."
أخبرنا الحسن بن محمد قال حدثنا حجاج عن ابن جريج قال أخبرني موسى بن عقبة عن عبد الله بن دينار
كنا حين نبايع رسول الله ﷺ على السمع والطاعة يقول لنا فيما استطعتم
Bukhari transmitted it in the Book of Judgments, chapter "How does the leader take the pledge of allegiance from the people?", no. 7202, and Muslim (see the previous hadith), from the hadith of Abdullah bin Dinar with the same wording. It is also found in al-Kubra, no. 7811.