Once the Prophet (ﷺ) got his blood out (medically) and paid that person who had done it. If it had been illegal, the Prophet (ﷺ) would not have paid him.
Sahih al-Bukhari Book 34, Hadith 56
← Previous Hadith Abu Taiba cupped Allah's Messenger (ﷺ) so he ordered that he be paid one Sa of dates and ordered his masters to reduce his tax (as he was a slave and had to pay a tax to them).

Sahih al-Bukhari Book 34, Hadith 55 Next Hadith → Once the Prophet (ﷺ) sent to `Umar a silken two-piece garment, and when he saw `Umar wearing it, he said to him, "I have not sent it to you to wear. It is worn by him who has no share in the Hereafter, and I have sent it to you so that you could benefit by it (i.e. sell it).

Sahih al-Bukhari Book 34, Hadith 57