Tafsir Al-Jalalayn: An-Noor, Ayah 61

Allah then revealed the following when the believers found it hard to eat with each other for fear of transgressing, because of Allah's saying (And eat not up your property among yourselves in vanity), and so Allah gave them dispensation to eat with each other saying: (No blame is there upon the blind) He says: there is no sin for the one who eats with the blind (nor any blame upon the lame) and there is no sin for the one who eats with the lame (nor any blame upon the sick) and there is no sin for the one who eats with the sick (nor on yourselves) a sin (if ye eat from your houses) from the houses of your children without asking permission but with moderation, (or the houses of your fathers, or the houses of your mothers, or the houses of your brothers) whether blood brothers, half brothers or milk brothers, (or the houses of your sisters) whether blood sisters, half sisters or milk sisters, (or the houses of your fathers' brothers, or the houses of your fathers' sisters, or the houses of your mothers' brothers, or the houses of your mothers' sisters, or (from that) whereof ye hold the keys) from that of which you hold the stores of what you have of wealth, i.e. male and female slaves, (or (from the house) of a friend) this was revealed about Malik Ibn Zayd and al-Harth Ibn 'Ammar who were friends. (No sin shall it be for you whether ye eat together) in moderation (or apart) and in this are included the blind, the lame, the sick and other categories of people. (But when ye enter houses) i.e. your houses or mosques and find no one there, (salute one another) say: �peace be upon us from our Lord� (with a greeting from Allah) as an honour from Allah to you, (blessed) with reward (and sweet) with forgiveness. (Thus Allah maketh clear His revelations) He exposits the commands and prohibitions just as He exposited this (for you, that haply ye may understand) what you have been commanded with.