مختصر صحيح بخاري
Mukhtasar Sahih Bukhari
Book of Fasting
Blessing in suhoor, but it is not obligatory.
Narrated Anas bin Malik (may Allah be pleased with him): The Prophet (peace and blessings of Allah be upon him) said: "(O people!) Eat Suhoor, for there is blessing in Suhoor. (By acting upon the command of the Messenger of Allah, there is practical benefit as well as reward in the Hereafter.)"