1 Kings 2:8

And behold [thou hast] with thee Shimei the son of Gera, a
Benjamite of Bahurim
Of whom, and of his native place, (See Gill on 2 Samuel 16:5); he was now at Jerusalem, and so with Solomon, or near at hand; and was on his side, and of his party; see ( 1 Kings 1:8 ) ; but not to be trusted, or looked upon as a real friend:

which cursed me with a grievous curse, when I went to Mahanaim;
a place on the other side Jordan, of which place, and the curses this man cursed David, with, see ( 2 Samuel 16:7 2 Samuel 16:8 ) ( 17:24 ) ;

but he came down to me at Jordan;
after the defeat of Absalom, and when David was returning, and humbled himself to him, and begged his pardon:

and I sware unto him by the Lord, saying, I will not put thee to death
with the sword;
but this oath was not binding upon his successor, and especially should he commit a new crime.