The Prophet (peace and blessings be upon him) said:
"Successful is the one who was granted guidance to Islam, whose provision was according to his need (kafaf), and who was content with it."
Hadith Referenceصحیح الجامع الصغیر / حرف الألف / 1138
Hadith Gradingالألبانی:صحيح
Hadith Takhrij[طب ك] عن فضالة بن عبيد. الصحيحة ١٥٠٦.