Imam Ibn ul Qayyim al Jawziyyah
`Uboodiyyah is a comprehensive term that asserts the meaning of the Aayah:
You Alone do we worship and You Alone do we seek for Help. (Qur’aan 1:5)
It comprises the slavery of the heart, tongue and limbs to Allaah ta`aala. The slavery of the heart includes both the Qawl (saying of the heart) and `Amaal (actions of the heart). The Qawl of the heart is the belief (I`tiqaad) in what Allaah has informed about His Self, His Names and Attributes, His Actions, His Angels, and that which He revealed in His Book and sent upon the tongue of His Messenger Muhammad sallallahu `alayhi wa sallam.
The `Amaal of the heart include love for Allaah, reliance upon Him, turning to Him in repentance, fearing Him, having hope in Him, devoting the Deen sincerely to Him, having patience in what He orders and forbids, having patience with His decrees and being pleased with them, having allegiance for His pleasure, having humility for Him and humbling oneself in front of Him, and becoming tranquil with Him.