Isa 49:3-4:

And he said to me, “You are my servant,

Israel, in whom I will be glorified.”

4 But I said, “I have labored in vain;

I have spent my strength for nothing and vanity;

yet surely my right is with the Lord,

and my recompense with my God.”

Heb 6:10

For God is not unjust so as to overlook your work and the love that you have shown for his name in serving the saints, as you still do.

https://pastorsteverhodes.com/2022/05/29/be-encouraged-what-you-do-does-matter/