Is tattooing forbidden and a major sin? And will a tattooed person be prevented from entering Paradise? And what is its expiation?

Tattooing is forbidden and is considered among the major sins, because the Prophet, peace and blessings be upon him, cursed the one who does it and the one for whom it is done. The one who does the tattooing or the one for whom it is done must repent to Allah and hasten to remove it, unless they fear severe harm, in which case sincere repentance is sufficient. As for entering Paradise, Allah accepts the repentance of one who repents from a major sin. As for one who dies persistent in it, their matter is up to Allah, but they will not remain in Hell eternally as long as they are a monotheist.