The phrase that caught my attention this time was "ye uncircumcised of heart." It is used once before in 2 Nephi 9:33. It says: 33 Wo unto the auncircumcised of heart, for a knowledge of their iniquities shall smite them at the last day.
Stephen in Acts 7:51 said: 51 ¶Ye stiffnecked and uncircumcised in heart and ears, ye do always resist the Holy Ghost: as your fathers did, so do ye.
Physical circumcision was a sign of conversion, belonging to the house of Israel. To be uncircumcised was breaking that covenant. Nephi was telling them that they had turned away from their faith, blinded by their sins. Bad things are coming their way and Nephi was trying to warn them.
Maybe it's like shaking the shoulders of someone you love who is making choices that hurt themselves. You want to just shake them and say "Why are you being so stupid? You know better. Stop it!"
Nephi loved his people, and all he wanted was for them to repent. He was bold and humble, speaking his mind but giving credit to God.
What did you think/learn today.