Ibn Katheer quotes Ibn Jareer at-Tabari, who said that all gratitude is due solely to Allaah, exclusive of all those who might be worshipped besides Him, for the inestimable blessings which He has bestowed upon His slaves – inestimable to all but Him – for the health which He brings to the bodily organs, that He might be obeyed, and the strengthening of the limbs of the body with which His Commands must be carried out. (And He has also blessed them with) the sustenance hich He has provided for them… without their being able to claim it as a right, and the means… which will lead them to everlasting life in the Eternal Abode. Therefore, for all this, praise is due to our Lord, first and last."
Ibn Jareer also said: Al-Hamdu Lillaah is praise: Allaah praises Himself and directs us to do likewise, as if He said: ‘Say: al-Hamdu Lillaah …’. Ibn `Abbaas said that Al-Hamdu Lillaah is the word of everyone who gives thanks and if anyone said: ‘Al-Hamdu Lillaah ,’ Allaah said: ‘My slave has thanked me.’ [Narrated by Ibn Abi Haatim]
The Prophet, sallallaahu `alayhi wa sallam also said: "The best remembrance (of Allaah) is Laa ilaaha illallaah (i.e. none is worthy of worship except Allaah), and the best supplication is Al-Hamdu Lillaah." (Narrated by Ibn Maajah, at-Tirmizi, An-Nasa’i and others)
From Tafseer Soorah al-Faatihah, Translated by Sameh Strauch
An Explanation of the Meaning of Soorah al-Faatihah, © 1998 IPH
Taken from the Tafaaseer of At-Tabari, Ibn Katheer & Ibn Al-Qayyim