Assalaamu alaykum. I have a question regarding theft in my circumstance. I was at a beach near a hotel with a hot tub in it. As many people coming out of the ocean get cold, they use the hotel's hot tub although there is a sign saying that the hot tub is only for hotel residents. I used the hot tub and then left without using any towels or eating food. My dad said that he thought it was alright because we have stayed there many times, and he also said that we are not taking anything from them because the jacuzzi is already there and is hot and it does not cost any more money for us to use it. If it is stealing, then how can I fix this mistake given that stealing requires restoring the person'ss rights back to them? And is repentance valid? Please answer, as I am confused. May Allaah reward you.

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger. 

Since the hotel that owns the hot tub prohibits the people who are not residing in the hotel to use it – and there is a sign indicating that – then you are not entitled to use it because this is transgressing other people’s properties without their permission. The Prophet, sallallaahu ‘alayhi wa sallam, said, “The money of a Muslim is not lawful (for anyone else to take it from him) unless he gives it with his own proper consent.” [Ad-Daaraqutni, Ahmad, and al-Bayhaqi - al-Albaani graded it saheeh (sound)]

The Prophet, sallallaahu ‘alayhi wa sallam, also said, “Your money, your wealth and your honor are sacred to one another…”

Therefore, you must seek the forgiveness of the owners of the hotel; if they forgive you, then this is what is required, otherwise you are obliged to pay them according to the extent of your use of their right (hot tub).

Ibn Abd as-Salaam said in Qawaa’id al-Ahkaam:

“The benefits are of two kinds: ........ The second kind: if the benefit is lawful and of value, then it must be compensated for whether in void or valid contracts, and whether it is misused by transgressors or taken advantage of (consumed) by them benefitting from it, because the sharee'ah valued it and considered it as wealth, so there is no difference between compensating it by contracts or by taking advantage of (consuming) it or misusing it.”

What you did is not called theft, but it is transgressing other people’s rights, which is forbidden. So you must repent from it and return the right to its owners or seek their forgiveness, as we have already mentioned, because the Prophet said, “If someone has wronged a person, then he has to seek his forgiveness for that injustice before the Day (of Judgment) on which there would be neither dinaar nor dirham. On that Day, if the unjust person has good deeds, then they will be taken from him, and if he has no good deeds, then the bad deeds of the person he wronged will be taken from him and transmitted to the wrongdoer.” [Al-Bukhari]

If you seek their forgiveness and they forgive you or if you return their right, then the repentance is valid.

Allaah knows best.