"Blessed" (tabaraka) is a verbal form derived from a word meaning blessing (baraka). It is said that it means something which is exalted, holy or lasting. Allah is the Lasting (dâ'im) whose existence has no beginning and whose everlastingness has no end. This expression, "tabaraka" is particular to Allah Almighty and it is not used in the present tense, but only in the past. Allah is exalted above all the attributes of creatures who are located in time and exalted above all else in His Essence, Attributes and Actions.
As He says, "There is nothing like Him." Some commentators say that this means that He is beyond annihilation or alteration. The form "tabaraka" indicates His perfection and immensity. Another example of this verb form which is only used for Allah is ta'ala, "Exalted is..."
We can look at the root of this verb and its meaning in two ways. There is the root burûk which means continuance or remaining. It is used to refer to birds remaining at water, to someone being firm and ready for fighting, and to someone who does not move where he is. This quality of being permanent reflects Allah's everlastingness. The other root is blessing or baraka. It is a blessing, either physical or spiritual, which continues, increases and abounds. So there is blessing which abides and ever increases. So Allah is abundant in good and exceeds everything in His continual goodness . As He says elsewhere: "All favour is in the Hand of Allah. He gives it to anyone He wills. Allah 's favour is indeed immense." (57:28)
"He who has the Kigndom in His hand" means the sovereignty or kingdom of the heavens and the earth, this world and the Next. It is said that it means the King of kings in this world, as you say, "the master of the kingdom." The first is more general and encompassing. He abases or exalts whomever He wills, He gives life and makes die, enriches and makes poor, gives and withholds. It is also said by some that He has the dominion of prophethood by which He exalts those who follow it and abases those who oppose it. He has the control of affairs. As He says elsewhere: "They do not measure Allah with His true measure. The whole earth will be a mere handful for Him on the Day of Rising, the heavens folded up in His right hand." (39:64)
In Arabic "hand" (yad) designates authority and power. Allah has the power to bless and take revenge. Commentators say that yad refers to Allah's power (qudra) which is His attribute without interpretation or qualification. His power is beyond description or limitation. In this context, Abu Hurayra reported in a sound hadith that the Messenger of Allah, may Allah bless him and grant him peace, said, "Allah's hand is full, undiminished by any expenditure since He created the heaven and the earth, for what His hand holds has not decreased. His Throne was upon the water, and in His hand the scale which He lowers and raises."
Mulk means sovereignty, kingship, dominion, and it is means ownership. It usually refers to this world, the physical world of bodies, whereas Malakut refers to the dominion of the unseen as He says, "Glory be to Him who has the Dominion (malakût) of all things in His Hand." (36:83)
"He has power over all things" defines His power - it extends to all things without limit. It reinforces the first sentence.