Full Idea
The most notable philosopher who makes God's commandment the basis of goodness, rather than God's goodness a reason for obeying him, is William of Occam.
Gist of Idea
William of Ockham is the main spokesman for God's commands being the source of morality
Source
William of Ockham (works [1335]), quoted by Alasdair MacIntyre - A Short History of Ethics Ch.9
Book Reference
MacIntyre,Alasdair: 'A Short History of Ethics' [Routledge 1967], p.119
A Reaction
Either view has problems. Why choose God to obey? Obey anyone who is powerful? But how do you decide that God is good? How do we know the nature of God's commands, or the nature of God's goodness? Etc.