We hear and we obey: listening only counts once it becomes doing
The Quran gives these words to people who have just been handed something hard. Agreeing with an instruction, admiring it, turning it over in your mind, all of that can go on for years while nothing in a life moves. The hearing finishes when the hands take it up, and before that a person is only standing near it.
Taqwā: Careful watchfulness about what God has warned against
The word points to the attention of someone walking a narrow path in the dark. Commands arrive as a whole set, and the quiet pull is to keep the ones that suit you and let one or two slip out the back. Watchfulness gives the small, unnoticed ones the same care as the ones everybody can see.
Ikhlāṣ: Sincerity, acting for God alone
Al‑Ghazali spends a long stretch of the Revival on how easily an act tilts toward an audience. The same obedience can be carried out to satisfy neighbors, to look solid in front of the community, or to keep anyone from having something to say. Sincerity means the deed comes out exactly the same when nobody is around to see it.
Murāqaba: Keeping God in view
The Prophet described worship as acting as though you see God, and knowing that He sees you. Right and wrong then stop being settled by whatever the people around you happen to approve of this year. Someone living this way measures their work against one gaze, and that gaze takes in the parts other people never reach.
My mercy has outrun my anger: mercy is God's first move
The Prophet passed these words on as God's own. After anything severe, a person is left braced, half expecting the next blow to fall on them, and obedience turns into flinching. Hearing that mercy is the older and stronger side of God changes what someone expects when they turn back and come close again.