David therefore departed from thence
 From Gath, being driven by Achish from his court, and let go by his servants, and glad he was of the deliverance: 
 and escaped to the cave Adullam;
 which was no doubt near to a city of the same name in the tribe of Judah, of which (See Gill on Joshua 15:35); this being a strong place, and in his own tribe, he might hope to be in greater safety; here he penned his hundred forty second psalm, see ( Psalms 142:1-7 ) : 
 and when his brethren and all his father's house heard [it];
 that he was come thither: 
 they went down thither to him;
 to visit and comfort him, counsel and assist him all they could; and chiefly to secure themselves from the rage and malice of Saul, who they might fear would fall upon them, and avenge himself on them for David's sake.