For strangers are risen up against me, and oppressors seek after my soul: they have not set God before them. Selah. Strangers are risen up against me - The Ziphites.
And oppressors - Saul, his courtiers, and his army.
They have not set God before them - It is on no religious account, nor is it to accomplish any end, on which they can ask the blessing of God.
Selah - This is true.