Abbas - Tanwîr al-Miqbâs min Tafsîr Ibn ‘Abbâs
(Whose hearts fear when Allah is mentioned) when they are commanded with any command from Allah, (and the patient) and give good tidings to those who are patient that they will have Paradise (of whatever may befall them) of hardship and misfortune, (and those who establish worship) and give good tidings to those who perform the five daily prayers, perfecting their ablution, bowings, prostrations and all that which is obligated in their prescribed times (and who spend) in alms and in giving the poor-due (of that We have bestowed on them) of wealth.
who, when God is mentioned, their hearts tremble, fear, and who endure [patiently] whatever may befall them, of ordeals, and who observe prayer, at its appointed times, and who, from that which We have provided them, expend, [from it] give voluntary alms.
(that they may mention the Name of Allah over the beast of cattle that He has given them for food.) It was recorded in the Two Sahihs that Anas said, "The Messenger of Allah brought two fat, horned rams; he said Bismillah and Allahu Akbar, then he put his foot on their necks.
فَإِلَـهُكُمْ إِلَـهٌ وَحِدٌ فَلَهُ أَسْلِمُواْ
(And your God is One God, so you must submit to Him Alone.) Your God is One, even though the Laws of the Prophets may vary and may abrogate one another. All of the Prophets called mankind to worship Allah Alone with no partner or associate.
(And We did not send any Messenger before you but We revealed to him (saying): None has the right to be worshipped but I, so worship Me.) 21:25. Allah says:
(so you must submit to Him Alone.) meaning, submit to His commands and obey Him in all sincerity.
(And give glad tidings to the Mukhbitin.) Mujahid said about Mukhbitin, "Those who find contentment in their faith.'' Ath-Thawri said, "Those who find contentment in their faith and who accept the decree of Allah and submit to Him.'' It is better to interpret it by what comes next, which is:
(Whose hearts are filled with fear when Allah is mentioned,) meaning, their hearts fear Him.
وَالصَّـبِرِينَ عَلَى مَآ أَصَابَهُمْ
(and the patient who bear whatever may befall them) meaning, of afflictions.
(and who perform the Salah,) they fulfill the duties which Allah has enjoined upon them, the duty of performing the obligatory prayers.
وَمِمَّا رَزَقْنَـهُمْ يُنفِقُونَ
(and who spend out of what We have provided for them.) the good provision which Allah has given them. They spend on their families and servants, and on the poor and needy; they treat people kindly while remaining within the limits set by Allah. This is in contrast to the hypocrites, who are the opposite of all this, as we have discussed in the Tafsir of Surah Bara'ah; to Allah be praise and blessings.
Maududi - Sayyid Abul Ala Maududi - Tafhim al-Qur'an
This verse implies two things:
(1) Sacrifice has been an essential part of the worship of One Allah in all the revealed religions. In order to inculcate Tauhid, Allah prohibited sacrifice for anyone other than Himself. This was in keeping with the other prohibitions which were made for others than Allah. For instance, "prostration" before anyone other than Allah, making vows for others than Allah, visiting holy places others than those prescribed by Allah, fasting in the name of others than of Alla, etc., were all prohibited.
(2) The other thing which has been common in all the revealed religions was the object of the sacrifice in the name of Allah though its details have been different in different religions, times and countries.
The Arabic word `mukhbitin' has no equivalent in English. It includes those who (1) give up pride, arrogance and adopt humility before Allah, (2) surrender themselves to His service and slavery, and (3) accept His decrees sincerely.
It means that righteous people spend their lawful provisions in the Way of Allah to meet their own and their dependents' lawful needs, to help their relatives, neighbors and other needy people, on public works and propagation of the Word of Allah. It does not include expenditure in unlawful ways for unlawful purposes. The Qur'anic term lnfaq implies neither over-spending nor being miserly and stingy, but spending one's wealth on oneself and others according to one's means and status in society.