السلام عليكم ورحمة الله وبركاته May Allah reward you immensely. If we study this books, can we teach them just to our wives and kids? Or do we need ijaazah/tazkiyah for that? بارك الله فيك

Ustadh AbdulAziz al-Haqqan

You can as long as u teach what u r positive of, and that which u do not know, u direct them to who know or say Allah knows best.