Jehovah
O Lord, thou didst hearken unto my words when I said, Let there be a famine, that the pestilence of the sword might cease; and I know that thou wilt, even at this time, hearken unto my words, for thou saidst that: If this people repent I will spare them. Helaman 11:14
Nephi prays to the Lord and holds Him to His own promise to spare the repentant. The Lord who made that covenant promise and turned away His anger (v. 17) is the God of Israel, whom Latter-day Saints know as Jehovah. Nephi addresses his prayer to 'O Lord,' so the Person is not explicit.
A readingJehovah — the LORDA divine namethe Father or the Son