1 Samuel 27:2

And David riseth, and passeth over, he and six hundred men who are with him, unto Achish son of Maoch king of Gath;

1 Samuel 21:10

And David riseth and fleeth on that day from the face of Saul, and cometh in unto Achish king of Gath;

1 Samuel 25:13

And David saith to his men, 'Gird ye on each his sword;' and they gird on each his sword, and David also girdeth on his sword, and there go up after David about four hundred men, and two hundred have remained by the vessels.

1 Samuel 30:8

and David asketh at Jehovah, saying, 'I pursue after this troop -- do I overtake it?' And He saith to him, 'Pursue, for thou dost certainly overtake, and dost certainly deliver.'

1 Kings 2:39-40

And it cometh to pass, at the end of three years, that flee do two of the servants of Shimei unto Achish son of Maachah, king of Gath, and they declare to Shimei, saying, 'Lo, thy servants are in Gath;'

Treasury of Scripture Knowledge

Summary

And David arose, and he passed over with the six hundred men that were with him unto Achish, the son of Maoch, king of Gath.

Bible References

The six

1 Samuel 25:13
And David saith to his men, 'Gird ye on each his sword;' and they gird on each his sword, and David also girdeth on his sword, and there go up after David about four hundred men, and two hundred have remained by the vessels.
1 Samuel 30:8
and David asketh at Jehovah, saying, 'I pursue after this troop -- do I overtake it?' And He saith to him, 'Pursue, for thou dost certainly overtake, and dost certainly deliver.'