{ Your women are a tilth for you, so approach your tilth whenever and however you wish } Al-baqara 223

It is said that if the vagina were designated in this verse as the place of tillage, it would be necessary to prohibit intercourse between someone's legs or the folds of their belly, since these are not the place of tillage, just as a sickle [i.e. is not a tillage implement]; this is refuted, since ejaculating without copulation is not regarded as sex or intercourse as commonly practiced. Allah Most High prohibited sex and intercourse in anywhere other than the place of tillage, not masturbation; a prohibition of masturbating between someone's legs or the folds of their belly can not be concluded from this verse, except if this is considered as sex and one proceeds deliberately to it.