Latin tutorial: https://www.youtube.com/watch?v=-72CWry11Fs
The reason / cause why something happens is expressed by the ablative; a preposition may or may not be used:
Sextus ex ventre labōrat. │Sextus has a pain in his stomach; literally: he is suffering from his stomach i.e. the stomach is the cause of the pain.
Mārcus ex capite labōrat. │ Marcus has a headache; literally he is suffering from his head i.e. the head is the cause of the pain.
Caeparius… dīxit tē in lectō esse, quod ex pedibus labōrārēs (Cicero) │ Caeparius … said you were in bed because you were suffering with your feet.
Mare ā sōle lucet. │ The sea gleams in the sun i.e. because of / from the sun.
Examples without prepositions:
Hoc fēcī amōre vestrī. │ I’ve done this out of love for you.
Exsiluī gaudiō. │ I jumped for joy.
ārdēre dolōre et īrā │ to be on fire with grief and (with) anger
