Abbas - Tanwîr al-Miqbâs min Tafsîr Ibn ‘Abbâs
(And) lo! those who believe) in Muhammad (pbuh) and the Qur'an, such as 'Abdullah Ibn Salam and his followers and Abu Bakr al-Siddiq and his companions (and do good works) acts of obedience privately between themselves and their Lord (are the best of created beings.
Mentioning the Worse and Best of Creation and Their Recompense
Allah informs of what will happen to the wicked disbelievers among the People of the Scripture and the idolators who oppose the Allah's divinely revealed Books and the Prophets whom He sent. He says that they will be in the fire of Hell on the Day of Judgement and they will abide therein forever. This means that they will remain in it and they will have no way out of it and they will not cease being in it.
أَوْلَـئِكَ هُمْ شَرُّ الْبَرِيَّةِ
(They are the worst of creatures.) meaning, they are the worst creation that Allah has fashioned and created. Then Allah informs about the situation of the righteous people who believed in their hearts and performed righteous deeds with their bodies. He says that they are the best of creation. Abu Hurayrah and a group of the scholars have used this Ayah as a proof that the believers have a status among the creatures that is better than the angels. This is because Allah says,
أُوْلَـئِكَ هُمْ خَيْرُ الْبَرِيَّةِ
(They are the best of creatures.) Then Allah says,
جَزَآؤُهُمْ عِندَ رَبِّهِمْ
(Their reward with their Lord) meaning, on the Day of Judgement.
(is Eternal Gardens underneath which rivers flow. They will abide therein forever,) meaning, having no end, no break and no conclusion.
رِّضِىَ اللَّهُ عَنْهُمْ وَرَضُواْ عَنْهُ
(Allah will be pleased with them, and they well-pleased with Him.) The condition of Him being pleased with them is more illustri- ous than all of the everlasting delights that they will be given.
(and they well-pleased with Him.) Due to the comprehensive favors He has given them. Then Allah says,
ذَلِكَ لِمَنْ خَشِىَ رَبَّهُ
(That is for him who fears his Lord.) meaning, this is the reward that will be attained by those who revere Allah and fear Him as He deserves to be feared. This is the person who worships Allah as if he sees Him, and he knows that even though he does not see Him, indeed Allah sees him. Imam Ahmad recorded from Abu Hurayrah that the Messenger of Allah said,
«أَلَا أُخْبِرُكُمْ بِخَيْرِ الْبَرِيَّةِ؟»
(Shall I not inform you of the best of creation) They said, "Of course, O Messenger of Allah!'' He said,
(A man who takes the reins of his horse in the way of Allah, and whenever there is a fearful cry from the enemy, he climbs upon it. Shall I not inform you of the best of creation) They said, "Of course, O Messenger of Allah!'' He said,
(A man who has a flock of sheep and he establishes the prayer and gives the obligatory charity. Shall I not inform you of the worst of creation) They said, "Of course.'' He said,
«الَّذِي يُسْأَلُ بِاللهِ وَلَا يُعْطِي بِه»
(The person who is asked by Allah and he does not give by Him.) This is the end of the Tafsir of Surat Lam Yakun (Al-Bayyinah), and all praise and thanks are due to Allah.
Maududi - Sayyid Abul Ala Maududi - Tafhim al-Qur'an
"Disbelieved": refused to acknowledge the Prophet Muhammad (upon whom be Allah's peace) as Allah's Messenger. The meaning is that the end of those from among the mushriks and the followers of the Book, who have not acknowledged the Messenger whose emergence by itself is a clear evidence, and who is reciting to them hallowed pages containing sound and correct teachings, will be as is being described below.
That is, they are worse than all creatures of God, even than animals, for the animals do not possess reason and power, but these people reject the Truth in spite of having reason and authority.
That is, they are superior to all creatures of God, even to the angels, for the angels do not have the power to disobey, and these people adopt Allah's obedience in spite of having the power to disobey Him.
In other words, the person who did not live in the world fearless and independent of God, but feared Him at every step lest he should do something which might entail His wrath and punishment, will have this reward resolved for him with Allah.