Al-Qalam Verse 3

You will certainly have a never-ending reward.

You will surely have a never-ending reward.

Surely thou shalt have a wage unfailing;

you will have a never-ending reward––

And verily thine shall be a hire unending."

Nay, verily for thee is a Reward unfailing;

and surely yours shall be a never-ending reward,

There is surely reward unending for you,

And indeed for you is an unlimited reward.

and yours indeed will be an everlasting reward,

And yours for sure is a reward constant and beyond measure.

(And) most surely, there awaits you a reward never to be cut off.

And that truly for you (is) a reward (E) not interrupted/weakened (continuous).

And indeed for you is an unlimited reward.

And most surely you shall have a reward unfailing.

And verily, for you (O Muhammad SAW) will be an endless reward.

So thou wilt see, and they (too) will see,

And most surely you shall have a reward never to be cut off.

And lo! thine verily will be a reward unfailing.

You will certainly receive a never-ending reward.

Indeed, there is an unfailing wage for you.

And verily, for you will be reward that is not Mamnun.

Most surely, you will have a never ending reward.

In fact, you will have a reward that will never end.

And assuredly you will have an unfailing reward.

And verily, for you will be reward that is not Mamnun.

meaning, `for you is the great reward, and abundant blessings which will never be cut off or perish, because you conveyed the Message of your Lord to creation, and you were patient with their abuse.'

The meaning of
غَيْرَ مَمْنُونٍ
(not Mamnun) is that it will not be cut off.

This is similar to Allah's statement,

عَطَأءً غَيْرَ مَجْذُوذٍ

a gift without an end. (11;108)

and His statement,

فَلَهُمْ أَجْرٌ غَيْرُ مَمْنُونٍ

Then they shall have a reward without end. (95;6)

Mujahid said,
غَيْرَ مَمْنُونٍ
(Without Mamnun) means

"Without reckoning."

And this refers back to what we have said before.
The Explanation of the Statement;"Verily, You are on an Exalted Character."

Concerning Allah's statement,

وَإِنَّكَ لَعَلى خُلُقٍ عَظِيمٍ