The Arabian pattern also can be executed away from the side of the board, or with the rook underneath the king, or with the knight flush against it—all shown here. The point is to take advantage of the complementary relationship between a knight and rook. The knight protects the rook; the knight also covers a pair of squares the rook can’t guard (h7 and g8 in this case), while the rook covers squares of a color the knight can’t reach (f8, h8, and g7). In this frame the pawn on g5 chips in as well.
Notice again the diagonal relationship between White’s knight and Black’s king—a signal to try to get a heavy piece onto a square the knight protects, as White has done here.