Learn Farsi: او از ماساژ خوشش می‌آید چون خسته است. - He likes the massage because he is tired.

In Farsi, 'to like' is an experiencer verb. Instead of saying 'He likes the massage', you literally say 'From the massage, his good comes'. خوش means 'good' or 'pleasant', and the ending ـَش is the 'his' pronoun attached to it. The verb می‌آید (it comes) is always in the 3rd person singular because the grammatical subject is technically the good feeling, not the person.

Why is there an از (from) before ماساژ (massage)?

The verb خوش آمدن (to like) requires the thing being liked to take the preposition از. You can think of it as the good feeling coming from the massage.

If the 'he' is already included in the ending of خوشش, why does the sentence start with او?

You do not strictly need او here; از ماساژ خوشش می‌آید is a perfectly complete sentence. Adding the independent pronoun او at the beginning just adds emphasis or sets up the topic, similar to saying 'As for him, he likes the massage.'

Could we say او ماساژ را دوست دارد instead?

Yes! دوست داشتن (to love/like) is a regular verb where the person is the subject, so او ماساژ را دوست دارد is grammatically correct. However, خوش آمدن is very commonly used for everyday things you find pleasant, enjoyable, or to your taste, like a massage, a movie, or a meal.