Hamd (praise) is more general and inclusive than shukr (thanks or gratitude), because thanks and gratitude are only a recompense for a favour, whereas hamd is both a recompense like thanks and is also spontaneous praise. Similarly, shukr may be more general and inclusive than hamd, because praise is expressed by the tongue, and thanks is expressed by tongue, heart and limbs.
If you understand the universal nature of hamd you will know that your saying "al-hamdu lillah" requires praise of Him for His majesty, vastness, unity, might, bestowal of favours, knowledge, ability and power, wisdom and other attributes, and that it encompasses the meanings of His ninety-nine beautiful names, and that it requires thanking Him and praising Him for every favour He has given and mercy He has bestowed upon all His creation in this world and the next. What a word [it is] which gathers together that which volumes find difficult to express, and the intellects of created beings concur upon as being unable to enumerate! Let it suffice you that Allah made it the beginning of His Book and the conclusion of the supplication of the people of the Garden 1 .
Thanks with the tongue is praise of the Bestower of Blessings and speaking about the blessings. The Messenger of Allah, may Allah bless him and grant him peace, said, "To talk about blessings is gratitude." 2 Thanks expressed by the limbs means to act in obedience to Allah and to abandon disobedience to Him. Thanks with the heart is recognition of the magnitude of the blessing and the knowledge that it is a gracious bestowal and not from the slave's own merit.
Know that the blessings which require gratitude cannot be enumerated, but they can be expressed in terms of three categories:
People have two ranks with respect to gratitude:
There are three degrees of gratitude:
One of the virtues of gratitude is that it is both one of the attributes of The Truth 4 [as well as] an attribute of people, because one of the names of Allah is ash-Shakir (the Recompenser, literally: the Grateful) and ash-Shakour (the Fully Grateful), both of which I have explained in the dictionary of terms (ash-Shakour is the name of Allah, "the One Who Recompenses His slaves for their actions with plentiful reward". It has also been said [that it means] "The One Who Praises the slaves").
Our saying, "Praise belongs to Allah the Lord of the worlds", is better, according to the people who ascertain [statements], than "There is no god but Allah" for two reasons:
As for the saying of the Messenger of Allah, may Allah bless him and grant him peace, "The best that I have said, I and the prophets before me, is 'There is no god but Allah'," 5 then that is only because of the tawhid which it contains, and "Praise belongs to Allah Lord of the worlds" participates along with it in that [meaning] and has increase beyond that. The believer says it seeking reward, but as for the one who enters Islam then he is required to say, "There is no god but Allah."
1 This refers to the supplication that the believers will make in the Garden, "Their prayer in it will be 'Glory be to You, O Allah,' and peace will be their greeting therein, and their prayer will conclude, 'Praise belongs to Allah the Lord of the Worlds.'" (Surah Yunus, ayah 10).
2 Part of a narration related by ash-Sha'bi on the authority of an-Nu'man ibn Bashir that the Messenger of Allah, may Allah bless him and grant him peace, said, "He who is not grateful for a little cannot be grateful for a lot, and he who is not grateful to people cannot be grateful to Allah [whereas] to talk about blessings is gratitude, and leaving it is ingratitude (kufr). The community (jama'ah) [leads to] mercy, and dissension [leads to] debasement." (Quoted by al-Qurtubi in his Jami' Ahkam al-Qur'an Tafsir 'ala Surah Wa'd-Duha.
3 Abu Ishaq Ibrahim ibn Adham. He was at one point the Amir of the region of Balkh in central Asia, but he turned to Allah and abandoned everything he possessed. Imam al-Junayd said of him, "Ibrahim is the key to the sciences" and he is held in great respect, by all who have knowledge, for his exemplary life and his incisive wisdom with respect to the states of man. He associated with Sufyan ath-Thauri.
4 Al-Haqq - "The True, the Real" is one of the names of Allah.
5 Related in the Jami' of at-Tirmidhi, in the Kitab ad-Da'awat.