He is the one who repays a good deed with a much greater reward. Thankfulness is to return good with good. To be thankful is a duty of man towards Allah. He is the one who created you and poured upon you all His bounties. He has left you free to see His gifts and to be thankful, or to be blinded by arrogance, denying even His existence.
Blessed is the one who chooses the path of thankfulness, spending what Allah bestows upon him in Allah's way. Then Allah ash-Shakur returns his thankfulness with rewards infinitely superior to his good deeds, and this in turn paves the way for further good deeds.
The thankful one knows that all he is and all he has is from Allah. He uses every part of his body - his mind, his tongue, his hands - only for the purposes for which they were created. He uses all that he has - his talents, his strength, his money - for Allah's pleasure on Allah's creation. Allah helps the thankful and increases their wisdom, their abilities, and their fortunes.
The ones who deny the bounties of Allah and hide them in secret rooms all for themselves are misers who pretend that they do not have anything. Therefore, although they have a lot, it is just as if they have nothing, so they want more and more. Never finding enough, they suffer destitution in the midst of abundance. Allah leaves them alone with their egos, their insatiable greed. All the bounties that they have received decay, stored in some secret place, unused. They pass from one loss to another, from one disaster to a worse one. If they do not take heed of these lessons, their unthankfulness will lead them to eternal damnation. We take refuge in Allah from such an eventuality.
'Abd ash-Shakur sees all good and nothing but good, and that all good comes from Allah. He is in a state of continuous thankfulness as was Hz. 'Ali (May Allah be pleased with him), who said: "All praise and thanks to Allah who presents His greatest favors to His beloved servants in the form of hardship and affliction, and presents to His enemies His punishment in the form of bounties."1
ASH-SHAKUR - The One Who Expresses Thankfulness by Rewarding Bounteously
Ash-Shakur is the one who rewards trivial pious deeds with many grades, and the one who gives unlimited happiness in the life to come for activity during a limited period (in this life). The one who rewards the good deed with multiples of it is said to be thankful for that good deed, and the one who praises the performer of this good deed is also said to be thankful for it. If you consider multiple rewards (to be the criterion in this matter), then there can be no absolute ash-Shakur except God Most High, because His increase of the reward is not restricted and limited since the blessings of Paradise are infinite. God Most High says, "Eat and drink at ease for that which ye sent on before you in past days."
(Furthermore), if you consider the concept of praise (to be the criterion), (you will discover that in the human realm) one's praises are directed to a second party, whereas when the Lord Most High praises the actions of His people, He is actually praising His own actions, since man's actions are a part of His creation. If one is given something and then praises (the giver), one may say that he is thankful. But the one who gives and then goes on to shower praises upon the recipient (certainly) is more worthy of being called a thankful person. The praise of God Most High upon His people is exemplified by His saying, "... Men who remember God much and women who remember, (God hath prepared for them forgiveness and a vast reward"), and by His saying, "How excellent a slave! Lo! he was ever turning in repentance (to his Lord)" and by other verses of this nature.
An Admonition: It is conceivable that man may be a thankful person in respect of another man, either by praising the second person for his good treatment of him or by rewarding the second person with a greater (benefit) than he received. (Actions of this nature) spring from man's praiseworthy qualities. The messenger of God said - may God bless him and grant him salvation! - "The one who does not thank man does not thank God." As far as thanking God is concerned, one can use this term only metaphorically and then only loosely. For even if man praises God, his praise is inadequate since the praise God deserves is incalculable. If man (expresses thankfulness by being) obedient, (even) his obedience is another one of the blessings of God Most High upon him. To be sure, man's thankfulness in itself is another blessing in addition to the blessing for which he is offering up his thanks. However, the best way of manifesting thankfulness for the blessings of God Most High is to make use of these blessings in obeying, and not disobeying, Him. And even this can only happen with God's help and by His making it easy for man to be a thankful person to his Lord. The idea underlying that statement is subtle.2