Nahj al-Balāgha
Hadith 2045٤٥٦. وَقَالَ (عليه السلام): أَلَا حُرٌّ يَدَعُ هذِهِ اللُّمَاظَةَ لِأَهْلِهَا؟ إِنَّهُ لَيْسَ لِأَنْفُسِكُمْ ثَمَنٌ إِلَّا الْجَنَّةَ، فَلاَ تَبِيعُوهَا إِلَّا بِهَا.
456. Amīr al-mu’minīn, peace be upon him, said: Is there no free man who can leave this chewed morsel (of the world) to those who like it? Certainly, the only price for yourselves is Paradise. Therefore, do not sell yourself except for Paradise.