Sandals and feet were considered dirty. Not worn in sanctuary. Lack of sandals considered sign of poverty.
Tearing the front neckline of your garment was a sign of grief or great offense. Wearing sackcloth and putting ashes or dust n the head was a mourning custom.
Baring the arm, wearing a girdle and taking off the simlah were all symbolic of being ready to work.
Wearing only a tunic was considered nakedness during and after the monarchic peroid. Wearing the simlah was the way to be presentable.