Where does “oraison” come from?

oraison (French) comes from Middle French oraison, from Old French oroison, from Latin ōrātiō, from Latin -tiō, from Latin dissertātiō, from Latin dissertus, from Latin disserere, from Latin dis- — small stone, pebble; gravel, rubble.

oraison (French): oration; orison, meditative prayer

Definitions

oration; orison, meditative prayer

Ancestry of “oraison”, step by step

Step	Language	Word	Meaning
1	Middle French	oraison	oration
2	Old French	oroison	prayer
3	Latin	ōrātiō	speech, discourse, language
4	Latin	-tiō	tion, -ation, -ing
5	Latin	dissertātiō	(spoken) dissertation, discourse, disquisition
6	Latin	dissertus	arranged, disposed; explained
7	Latin	disserere	second-person singular future passive indicative...
8	Latin	dis-	asunder, apart, in two; reversal, removal;...
9	Latin	calceus	shoe
10	Latin	calx	limestone; chalk; the finish line
11	Ancient Greek	χάλιξ	small stone, pebble; gravel, rubble

Every word from Ancient Greek χάλιξ →Every word from Latin -tiō →Every word from Latin dis- →