The Messenger of Allah ﷺ said, "Successful is the one who has been guided to Islam, granted enough to sustain him, and content with what he has been given."
حدثنا محمد بن رمح حدثنا عبد الله بن لهيعة عن عبيد الله بن أبي جعفر وحميد بن هانئ الخولاني أنهما سمعا أبا عبد الرحمن الحبلي يخبر
عن رسول الله ﷺ أنه قال قد أفلح من هدي إلى الإسلام ورزق الكفاف وقنع به
No references are available.
Muslim reported it in his book on zakat, in the chapter on sufficiency and contentment, hadith no. 1054/125, from Abu Abdul-Rahman Hubli, with different wordings but a similar meaning.