These hands are those of different girls.Certain beleive that in order to get married and chase away bad omen they have to put some "hena"on their hands and ask the marabout to endow them with luck and a husband to share life with.The girls give offrands to people responsible of the marabout ,these offrands can be sugar and candles and sometimes money.finally they put their hand on the "sacred"walls of the marabout beleiving that in doing so the bad spirit will be imprisonned in the wall .