"Let me recommend you, however, as a friend, not to give implicit confidence to all his assertions..." (pg. 95)
In this scene, the extremely haughter Miss Bingley is telling Elizabeth that she shouldn't believe everything that Wickham tells her. Austen employs foreshadowing in this passage to let the audience know that, even though Elizabeth trusts Wickham and what he's told her about Darcy, Wickham is not to be trusted. Of course, the audience later finds out that not only did Wickham waste the money that Darcy's father left him and the money Darcy lent him but he attempted to run off with Georgiana, only to break her heart and marry Elizabeth's sister Lydia.