It turns out the mustard seed is mentioned several times throughout the bible as a symbol of faith. Though the seed is a symbol of faith in Christianity, it is also known to signify good luck in the secular community.
In Matthew 17:20, Jesus said, “If you have faith as a small as a mustard seed, you can say to this mountain, move from here to there and it will move. Nothing will be impossible for you." Ephesians 2:2, "Our God able to exceedingly and abundantly above all we ask or think."