Al-Qalam - 68:3

وَإِنَّ لَكَ لَأَجْرًا غَيْرَ مَمْنُونٍ
[68:3]
And most surely you shall have a reward never to be cut off.
Nay, verily for thee is a Reward unfailing:
And lo! thine verily will be a reward unfailing.