1 Nephi 3:18

¨For behold, they have rejected the words of the prophets. Wherefore, if my father should dwell in the land after he hath been commanded to flee out of the land, behold, he would also perish. Wherefore, it must needs be that he flee out of the land."

Unlike the people of Nineva, who heeded the voice of Jonah, the prophet, and repented of their sins and became righteous, the people of Jerusalem rejected the call of repentance. The evil planted in their hearts led up tot the need of Lehi to flee the land for safety.  By fleeing our of Jerusalem Lehi's life was spared and also that of his family. If Lehi had ignored the warning of God, then the tender mercies of the Lord would not take effect and Lehi would have been in Jerusalem when it was destroyed. 

#Gloss

same not people NINEVA listen finish voice Jonah, himself prophet, repent sins finish become right do people J-city rebel repent. Evil finish inside heart lead need Lehi himself leave land for-for? Safe. Happen leave J-city Lehi life save can same family save. If Lehi ignore Lord, His warn mercy not happen. Lehi stay J-city happen city itself destroy. Finish.