Allah Most High has said: Say: Praised be Allah! [27:59] and: If you would count the blessings of Allah you would not be able to reckon them, [14:34] and: Of the blessings of your Lord, speak out, [93:11] and: Remember Me, and I will remember you, give thanks to Me, and reject Me not, [2:152] together with other verses concerning Allah’s gifts to His slaves, and His reminding them thereof.

Bukhari relates that Abu Dharr, radhiallahu `anhu, said, "Whenever the Messenger of Allah, sallallahu `alaihi wa sallam, went to bed at night, he would say, ‘In Thy name do I die and am I given life again,’ and when he awoke he would say, ‘Praised be Allah Who gave me life after He caused me to die. And unto Him shall be the resurrection.’"

Muslim relates the following hadith from Suhayb, radhiallahu `anhu, "The affairs of a believer are astonishing, and are all good; this is something which is true of him alone. For when something good comes to him he gives thanks, while when something bad comes he is steadfast, which is good for him also."

Abu’l-Hasan al-Kindi recited the following lines:

If you have been given blessings, then look after them
  for sins do away with blessings.

Al-Junayd said, "I once heard al-Sari saying, ‘Because to give thanks for blessings is itself a blessing, one can never cease to give thanks."

Imam al-Shafi`I writes at the beginning of his Treatise [Risalah, one of the formative texts of Islamic legal theory]: "Praised be Allah, Who, whenever He is thanked for one of His blessings, provides another blessing which in turn obliges one to thank Him again!"

According to Ibn Abi’l-Dunya, the following verses were composed by Mahmud al-Warraq:

If my thanking Allah for His blessings is a blessing,
  then I must thank Him in the same measure again.

How can one thank Him save by His grace
  as time goes on, and life goes by?

If a good thing comes, I rejoice heartily;
  if a bad one comes, I receive a reward.

In both cases He gives me a gift too large
  for the minds of men, and the land and sea.

In another version, the last three verses are replaced by the following:

My only excuse is that I am inadequate
  but my excuse is a confession that I have no excuse.