"Wherefore, let us be faithful in keeping the commandments of the Lord; therefore let us go down to the land of our father's inheritance, for behold he left gold and silver, and all manner of riches. And all this he hath done because of the commandments of the Lord."
The Lord knows everything. By having Lehi leave behind his worldly wealth He provided a way for a trade for the brass plates. Interesting that beyond the need to travel lighter the thing about leaving the wealth did, in fact, give them a way that a trade could be possible. This probably didn't even occur to them and they packed up to leave. Nephi was probably prompted by the spirit to think of the trade. By following the commandments of the Lord are His followers blessed.
Lord self know everything. Reason Lehi leave rich, gold, silver, things. Lord give way trade can. interesting. need travel not heavy with gold, silver, yes but also Lord knew best way, trade can. Thought happen not same time pack leave. Nephi prompt maybe spirit think trade. Happen follow commandment from Lord His follow-person bless will.