What does Salan give to Omar before Omar leaves for America as noted in the memoir, When Stars Are Scattered?

At the end of the memoir, when Omar is about to leave, Salan hands him a bottle of sand from Dadaab as a gift, telling him, “May your blessings be as countless as the grains of sand in the desert and the stars in the sky” (251). The symbol of the grain of sand - and later the bottle of sand from Salan - therefore represents the culmination of the community (including him) who have helped Omar along the way, and who he will always have with him.