Allah inspired Prophet Musa (pbuh) saying,
“Do you know, O Musa, why I chose you from among My
creation to hear My word?”
“No! Ya Rabb,” said Prophet Musa (pbuh)
Allah said: “From the inhabitants of the earth, I found none
more humble than you.”
Prophet Musa (pbuh) went immediately into sajda, and rubbed
his cheeks on the earth as a sign of humility to his Rabb, the
Supreme.
Allah said, ”O Musa! Raise your head and pass your hand over
the place where you did sijda, then wipe your face with it and
whatever you can touch of your body, for this will be your
security against any sickness or ailment, affliction or handicap.
Excellent Stories Vol 1