דברי הימים א, פרק י״ב, פסוק י״ז

During David's flight from King Saul, various supporters gathered to join his side. A unique delegation made up of men from both the tribe of Benjamin and the tribe of Judah arrived at the hidden fortress where David was taking shelter [רש״י, מלבי״ם].

The primary approach among commentators is that this joint arrival was a highly calculated move rather than a coincidence. Because the men of Benjamin belonged to the same tribe as King Saul, they were concerned that David would suspect them of setting a trap. They feared he might think they were using deception to capture him and hand him over to the king. To eliminate any suspicion and prove their good intentions, they brought along the men of Judah, led by Amasai, who was a relative of David. The strategy was straightforward: by seeing his own family members arriving alongside the men of Benjamin, David would understand that the group came in good faith and could be trusted without any doubt.