Jewish NFL star Julian Edelman says the anti-Semitic slur uttered by Meyers Leonard is the result of "casual ignorance" ... and he's offering to educate the NBA player on Jewish history so he doesn't make the same mistake twice.

Edelman says he's never met Leonard before -- but he's clearly caught up on the scandal surrounding the Miami Heat player, who used the anti-Semitic K-word to attack an opponent during a video game live stream this week.

Leonard later issued an apology -- claiming he was not aware of the hateful history of the word and vowed to educate himself about it.

"I'm sure you've been getting lots of criticism for what you said," Edelman said in an open letter to Leonard ... "Not trying to add to that, I just want to offer some perspective."

"I get the sense that you didn't use that word out of hate, more out of ignorance. Most likely, you weren't trying to hurt anyone or even profile Jews in your comment. That's what makes it so destructive."

Edelman continued, "When someone intends to be hateful, it's usually met with great resistance. Casual ignorance is harder to combat and has greater reach, especially when you command great influence."

"Hate is like a virus. Even accidentally, it can rapidly spread."

Edelman ended his letter with an offer to Leonard -- "I'm down in Miami fairly often. Let's do a Shabbat dinner with some friends I'll show you a fun time."