Wholesome is absence of passion?

I'm answering the question based on No need to have passion to answer the question, of cause. comment in the question. I might not have references to what I say in english, as the english Sutta are lacking some suttas. I'll try to point to the suttas anyway.

A person told here, that wholesome (kusala) means absence of passion (desire, will..., raga, lobha, chanda...).

.

Is that right?

Yes, This is correct, but instead of raga, lobha, chanda we can conclude everything to Thrushna = Thanha = Craving And it can be again divided to Ragha, Dwesha, Moha. When you are uprooting these, it will become Kusala as its the only thing which helps to achieve Nivana = Enlightenment

If why?

How Nivana = Enlightenment is defined in Samyutta Nikaya - 4 -> Asankatha Sutta is: Not making the mind dirty with Ragha, Not making the mind dirty with Dwesha, Not making the mind dirty with Moha is Nivana = Enlightenment How its written in Pali is Raghakkhayoo Nibbanan, Dweshakkhayo Nibbanan, Mohakkayo Nibbanan. So when there's Ragha, Dwesha, Moha occurs in our mind, it cause us to lose the Kusala. Next If we look at why Ragha, Dwesha, Moha occurs in our mind? That's because of the Avijja = Ignorance And that remains bit hard to explain, as I can't give reference as the English translation is missing some sutta.

If I explains simply what we ignore about the world is, we think the world is worth, (car is worth, children are worth etc.) and we get attached to those. Actually there's no worth in external world. But thinking that out side world is worth we create our own world (five aggregates of clinging) and get attached to that.

Next why we think the outside world is worth? It's because with think the external world gives us happiness that's why we think it's worth. But actually external world behaves as the way its supposed to be (according to the Pratītyasamutpāda). But we get cheated thinking the external world is behaving the we want and get attached to that. (eg: when someone has car he thinks the car is worth and it behaves as he wants it, actually its not because he wants it, but it's how it supposed to happened according to the law of nature = Pratītyasamutpāda. Not knowing this behaviour is called Avijja)

Please don't just ignore this. This is the base of the Buddha's teaching. And it's not the way it's written, but its the way someone feels and understand it. (eg: addition of 1 + 1 = 2, is very proven to everyone, no matter the language, no matter Einstein says we know that is it, because we've realised it and proven to our selves. If someone asks us to believe that 1+1 is not 2 but 3, then it's not gonna happen, as we've clearly understand 1+1 = 2. Like wise, Aijja is as explained above. When you realise it, no matter what, you know it and understand it and you see that in the world : day-to-day action )

With Metta..!

Sutta Pitaka Vol 14 : Sutta. Aṅ. (3): pañcakanipātā SamaapattiSutta:

aṅguttara nikāya

the book of the fives

6.Entering

(1) “Bhikkhus, there is no entering upon the unwholesome so long as faith is securely settled in cultivating wholesome qualities. But when faith has disappeared and lack of faith obsesses one, then there is the entering upon the unwholesome.

(2) “There is no entering upon the unwholesome so long as a sense of moral shame is securely settled in cultivating wholesome qualities. But when a sense of moral shame has disappeared and moral shamelessness obsesses one, then there is the entering upon the unwholesome.

(3) “There is no entering upon the unwholesome so long as moral dread is securely settled in cultivating wholesome qualities. But when moral dread has disappeared and lack of moral dread obsesses one, then there is the entering upon the unwholesome.

(4) “There is no entering upon the unwholesome so long as energy is securely settled in cultivating wholesome qualities. But when energy has disappeared and laziness obsesses one, then there is the entering upon the unwholesome.

(5) “There is no entering upon the unwholesome so long as wisdom is securely settled in cultivating wholesome qualities. But when wisdom has disappeared and lack of wisdom obsesses one, then there is the entering upon the unwholesome.”

Keep in mind chanda, like "desire" in english, can be good or bad. kāma-chanda, sensual or sexual desire, is different than the chanda infused with good in the four iddhipada for example: chanda-samadhi-padhana-sankhara-samannagatam (desire based samadhi...)

Even rāga (passion), occasionally is used in a good sense. Dhamma-rāga, for example, even a non-returner can still have some passion for Dhamma-teachings.

So the question you asked is interesting, I'm not sure kusala or akusala has an airtight definition in the suttas.

The way I understand, any action which benefits you and the other person or both are wholesome.