Delaying Witr Salaah until Tahajjud Time

Q: Is it jaaiz (permissible) to delay witr salaah until tahajjud time?

A: If one is sure of waking up for tahajjud then it is actually better to delay the witr salaah and perform it after completing tahajjud but before subuh sadiq. If one does not have this assurance then better to perform it before sleeping.