1 Chronicles 12:18
Then the spirit came upon Amasai, who was chief of the captains, and he said, Thine are we, David, and on thy side, thou son of Jesse: peace, peace be unto thee, and peace be to thine helpers; for thy God helpeth thee. Then David received them, and made them captains of the band.
Cross-reference
In 1 Chronicles 12:38, the same gathering is summarized: warriors came wholeheartedly to make David king, directly continuing the narrative of Amasai's declaration.
Judges 6:34 also says 'the Spirit of the Lord came upon' a leader — Gideon, as Amasai is empowered here.
Ittai's oath in 2 Samuel 15:21 echoes this same total allegiance to David, promising to follow him through life and death.
In 1 Samuel 25:6, David sends a triple peace blessing to Nabal, mirroring Amasai's triple peace to David. Both use the same distinctive blessing formula involving David.
Judges 13:25 describes the Spirit stirring Samson — similar empowerment but different verb.
In Psalm 122:7, the blessing of peace for Jerusalem echoes the triple peace blessing Amasai pronounces over David.