'Signal' in the Bible

Meanwhile, some kidnappers were hiding inside an inner room, waiting for her signal. So she told him, "The Philistines are attacking you!" But he snapped the cords as one might break a burned candle wick. So his secret remained undiscovered.

The men of Israel had a prearranged signal with the men in ambush: when they sent up a great cloud of smoke from the city,

But when the signal began to rise out of the city in a column of smoke, the Benjaminites looked behind them; and behold, the whole of the city went up in smoke to heaven.