So today with my pellet gun I killed a rabbit and than threw the body away in my back yard and I feel terrible for killing the rabbit and I would like to know what should I do to get forgiveness from Allah for doing it?
Praise be to Allaah.
Undoubtedly this action that you did is something which is forbidden according to sharee’ah and is not permitted. This is a form of tormenting animals which the Prophet (peace and blessings of Allaah be upon him) forbade.
(Narrated by al-Bukhaari, 5195; Muslim, 1958. The version narrated by Muslim says, “The Messenger of Allaah (peace and blessings of Allaah be upon him) cursed those who do that.”)
The Messenger of Allaah (peace and blessings of Allaah be upon him) forbade detaining or tying up animals (for the purpose of killing them); according to another report, ‘Do not take anything in which there is a soul as a target.’ The scholars said that tying up animals means restraining them whilst they are still alive in order to use them as targets and so on. The words ‘Do not take anything in which there is a soul as a target’ means do not use living animals as targets for shooting as targets made of leather and so on are used. This prohibition means that doing this is haraam. Hence the Prophet (peace and blessings of Allaah be upon him) said, according to the report narrated by Ibn ‘Umar which follows this report: “Allaah cursed the one who does that.” And because it is torturing animals, a waste of their [animals’] lives, a waste of money, causing the animal to die without slaughtering it in the proper Islamic manner if it is an animal whose meat may be eaten, and wasting an animal from which benefit may be derived in other ways if it is an animal whose meat may not be eaten.
Sharh Muslim, 13/108
You must repent sincerely to Allaah from this deed and seek His forgiveness, and do lots of good deeds so that Allaah will forgive your sin.
And Allaah is the Guide to the straight path