Man Proposes, God Disposes (Origin of Saying)
"A man's heart plans his way, but the LORD directs his steps." (Pro. 16:9)
"Le coeur de l'homme se propose sa voie, mais l'Éternel dispose ses pas. (Proverbs 16:9, Darby)
Means: The heart of a man proposes or plans his way, but God disposes or directs his steps (brings about his goings).
Seems like this is the origin of the saying "Man proposes but God disposes."