1 Nephi 15:3

For he truly spake many great things unto them,

which were hard to be understood,

save a man should inquire of the Lord;

and they being hard in their hearts,

therefore they did not look unto the Lord as they ought.

and they being hard in their hearts,

hearts - 4 occurrences in 4 verses - 1 Nephi 15:3, 4, 10, 11