What is the ruling on repeating prayers invalidated due to ignorance of the obligation of ghusl (ritual bath) after masturbation before puberty, and is such ignorance considered an excuse?

If someone omits a condition out of ignorance, there is a difference of opinion among scholars regarding the necessity of repeating the action. Imam Ibn Taymiyyah's view is strong, while the view of the majority is more cautious. The ignorance here is not excessive. One should follow the fatwa of someone they trust, and performing the act again as a precaution is better. The mere act of sexual intercourse does not necessitate ghusl (ritual bath) unless semen is discharged. If there was no ejaculation, then the issue does not arise. If there is doubt about ejaculation, the default assumption is that it did not occur. Doubt about an act of worship after its completion does not affect its validity.