Whilst there are a few exceptions, generally speaking, Cookers, Ovens and Hobs are not supplied with a cable.
There are a couple of primary reasons for this. Firstly, under current legislation, any item which is hard wired to a cooker point or similar must be installed by a suitably qualified and certified Electrician, who will provide the correct cable for the job. Whilst it may be tempting to install items yourself, doing so, and not doing it properly will invalidate your Warranty, and possibly even your Household Insurance. Secondly, no seller can know how much cable would be required for any particular installation, so it is pointless supplying what may be a cable that is inappropriate for the job in hand.
The main exception to this rule is items which have a low power rating and can be plugged into a 13 amp socket. These are generally supplied with a cable.