Sometimes, you don’t have to be harsh to point out.
“Bro, that’s really harsh words. If you are asking for help, that’s not the right attitude”
or
“Bro, the way you spoke scares me. If you are asking for help, I am afraid that is not going to work”
Or
“Yoh bro, gotta be nice when you are asking for help, or it won’t work for me”
or simply an excuse.
“Sorry bro, I am really busy right now with other stuffs. You will have to handle them on your own for now”
I think silenced, bad expression, speak harshly are far worse actions especially in the same company. You don’t want to create enmity that might bite you in the long run. Imo