[Charity is] for the poor who have been restricted for the cause of Allāh, unable to move about in the land. An ignorant [person] would think them self-sufficient because of their restraint, but you will know them by their [characteristic] sign. They do not ask people persistently [or at all]. And whatever you spend of good - indeed, Allāh is Knowing of it.
Abu `Abdur-Rahman An-Nasa'i recorded that Ibn `Abbas said that they, "Disliked giving charity to their polytheist relatives, but were later on allowed to give it to them when they inquired about this matter, and this Ayah was revealed,
(Not upon you (Muhammad ) is their guidance, but Allah guides whom He wills. And whatever you spend in good, it is for yourselves, when you spend not except seeking Allah's Face. And whatever you spend in good, it will be repaid to you in full, and you shall not be wronged.)
needy who are confined in the way of Allah ... Allah is All-Aware of it”.
Here the word, al-fugara الفقراء ' (the needy: those who need support for their physical sustenance) covers all those who cannot engage themselves in other jobs because of their religious preoccupation.
يَحْسَبُهُمُ الْجَاهِلُ أَغْنِيَاءَ مِنَ التَّعَفُّفِ : "An ignorant person takes them to be rich on account of their abstinence."
This verse tells us that a faqir فقیر (the one who does not own the nisab نصاب of زکاۃ Zakah) wearing expensive dress will not be taken as 'need-free' because of that. Instead, he would be regarded as faqir فقیر . Paying زکاۃ Zakah to such a person will be correct. (Qurtubi)
تَعْرِفُهُم بِسِيمَاهُمْ "You know them by their appearance."
This tells us that it is correct to give rulings based on circumstantial evidence. For instance, if a dead body is found wearing zunnar (waist-cord which is a symbol of some pagan religions), and is uncircumcised, it will not be buried in the graveyard of Muslims. (Qurtubi)
لَا يَسْأَلُونَ النَّاسَ إِلْحَافًا :"They do not beg people importunately."
On the surface, this verse gives the sense that they do not solicit importunately but it does not negate soliciting without importunity, as is the actual interpretation of some commentators. But, in accordance with the consensus of commentators, it means that they just do not ask; لاَنھم متعففون عن المساَلہ عفۃ تامۃ (totally refrain from asking) (Qurtubi).
Tazkirul Quran
Maulana Wahiduddin Khan
There are two ways of spending one’s earnings in this world. One is to spend in ways shown by Satan. Another is to spend in ways shown by God. What Satan does is to impress on the minds of human beings the importance of personal requirements, and bring about conviction that all their earnings are best spent on personal comforts and luxuries.
Uthmani text of the Madinah mushaf (King Fahd Complex). Translation: Saheeh International. Tafsir via Quran.com.