B"H
It says in the Gemara (Shabbat 88a) that when the people of Yisroel said "we will do" (na'aseh) before "we will listen" (nishmah), 600,000 angels came and tied two crowns to each of their heads; one corresponding to "we will do" and one corresponding to "we will listen".
The fact that it says that there are only two, one for the very fact that they said "we will do" and one just because they said "we will listen", then what did they get as a reward for saying "we will do" before we will listen?
Seemingly even if they would have said "we will listen" first, they would still have received two crowns.
So what did they get for prefacing "we will do"? Would they still have gotten two crowns even if they didn't?