How do you know when your thoughts comes from the Yetzer Tov, good; or the Yetzer Hara, the demon that tries to convince to not do good but uses “reighetsnous” as an excuse, for example, “you shouldn’t give charity because you need to support your family” – so the answer is two things: firstly, when did you think of the excuse, if it is precisely when you decided to give the money away, however when you spent the money on pleasures you didn’t think this, it is a clear sign it’s only from the Yetzer Hara; additionally, it is easy to discern, for all thoughts which cause goodness and kindness come from the Yetzer Tov and all thoughts that cause lack of goodness and kindness are from the Yetzer Hara.