The Messenger of Allah (may Allah's peace and blessings be upon him) used to offer the Duha Prayer as four Rak‘ahs and sometimes as much more as Allah willed
Authentic hadithعن عائشة رضي الله عنها قالت: كان رسول الله صلى الله عليه وسلم يُصلِّي الضُحى أربعا، ويَزِيد ما شاء الله.
‘Ā'ishah (may Allah be pleased with her) reported: The Messenger of Allah (may Allah's peace and blessings be upon him) used to offer the Duha Prayer as four Rak‘ahs and sometimes as much more as Allah willed.
Explanation
In this Hadīth, ‘Ā'ishah (may Allah be pleased with her) informed that the Prophet (may Allah's peace and blessings be upon him) used to perform the Duha Prayer as four Rak‘ahs, making Taslīm after every two Rak‘ahs. She also mentioned that he would sometimes pray more than four Rak‘ahs, according to his ability and how active he felt.
Source · Narrated by Muslim
From the Hadith Encyclopedia (hadeethenc.com).