'An horror of great darkness fell upon him.' Genesis 15:1
Whenever God gives a vision to a saint, He puts him, as it were, in the shadow of His hand, and the saint's duty is to be still and listen. There is a darkness which comes from excess of light, and then is the time to listen. Genesis 16 is an illustration of listening to good advice when it is dark instead of waiting for God to send the light. When God gives a vision and darkness follows, wait. God will make you in accordance with the vision He has given if you will wait His time. Never try and help God fulfil His word. Abraham went through thirteen years of silence, but in those years all self-sufficiency was destroyed; there was no possibility left of relying on common-sense ways. Those years of silence were a time of discipline, not of displeasure. Never pump up joy and confidence, but stay upon God (cf. Isaiah 1:10,11).
Have I any confidence in the flesh? Or have I got beyond all confidence in myself and in men and women of God; in books and prayers and ecstasies; and is my confidence placed now in God Himself, not in His blessings? "I am the Almighty God" - El-Shaddai, the All-Powerful God. The one thing for which we are all being disciplined is to know that God is real. As soon as God becomes real, other people become shadows. Nothing that other saints do or say can ever perturb the one who is built on God.