Please tell me what's meaning of this sentence.
Also, the parties shall not in any manner solicit nor accept any business from[ sources or their affiliates that are directly or indirectly introduced by the other party or parties who directly introduced the source].

Question

Answer

What's "the source"?
I presume this is part of a contract between two parties.
A little background?
You are not to buy stuff from anyone they introduce you to, or you hear about because of this deal.
That is, you can't go round them after they tell you where they buy stuff.
.
Better background, better answer.