Yes, of Gentiles also. But to the one who does not work, but believes in Him who justifies the ungodly, his faith is credited as righteousness. To the one who works, his wage is not credited according to grace, but according to debt. Therefore, working does not exclude boasting, it supports boasting. On the other hand, faith does not call attention to itself, but to the grace of the one trusted.
Faith corresponds to grace.
Work corresponds to debt. Therefore faith excludes boasting, and work supports boasting. If you are the beneficiary of grace in all that you are and have, you cannot boast in yourself. When all is gift, boasting is excluded. Don't nullify grace and turn justification into a debt.