I set my face like a flint

FLINT ARROW HEAD FOUND IN ROGESTORPS MOSSEN (ROGESTORP BOG) THE YEAR 1940, 4 KM SOUTH OF FALKÖPING, ...Image via Wikipedia

In reading scriptures today I came across this verse and wondered what it meant to be like flint.

For the Lord God will help me, therefore shall I not be confounded. Therefore have I set my face like a flint, and I know that I shall not be ashamed.

(Book of Mormon | 2 Nephi 7:7)

I found this web site:

Set Your Faith and Trust Like Flint! « Thoughts, Words & Devotions by Tim Burt

Flint is a variety of quartz that, due to its extreme hardness, is easily shaped by flaking. Known and used since very ancient times, flint was used by the Israelites for knives, ax heads, arrow heads, spear heads and starting fires. God wants us to be immovable by circumstances instead standing hard core like flint in His promises. .... When we draw close to Him with that kind of tenacity, God will help us see the cup half-filled while He is filling it the rest of the way. Our face will be set like flint and our faith ignited.

I think it interesting that flint flakes off easily but in one direction.  The Lord wants us to be focused, being hard and tenacious in following him, but easily bent to his will (flake off) but only his will (one direction.)