1 Kings 2:39

And it came to pass, at the end of three years
He had dwelt at Jerusalem:

that two of the servants of Shimei ran away to Achish the son of
Maachah king of Gath; and they told Shimei, saying, behold, thy servant
[be] in Gath;
he being a churlish, ill-natured man, always cursing or beating them, or imposing too hard service upon them, or not allowing them the necessaries of life; wherefore they broke away from him, and fled to Gath, and put themselves under the protection of the king of that place, who was now at peace with Israel, and a tributary to them: if this Achish was the same that was David's friend, who sheltered him when persecuted by, Saul, he must be an old man; for that was between forty or fifty years ago; and as he seems to be, since he is called the son of Maoch, ( 1 Samuel 27:2 ) ; which may be thought to be the same with Maachah here.