They also posted on Twitter before the game with the instruction: "A call to all away supporters. Take with you a little cuddly toy to the game.
"Just make sure there are no hard things in the toy. So no beads and buttons, children from the Sophia Children's Hospital will be under us in the away end."
In the match itself Feyenoord ran out 3-1 victors with former Liverpool striker Dirk Kuyt getting on the scoresheet.
Giovanni van Bronckhorst's team are sitting pretty at the summit of the Eredivisie and have a perfect record.
Feyenoord have won all five of their opening games whilst Den Haag have also enjoyed a positive start and lie in fourth place.