Al-Aḥzāb: 55
"There is no blame upon them..."
It is narrated that when the verse of the veil (ḥijāb) was revealed, the fathers, sons, and relatives said: "O Messenger of God, are we also to speak to them from behind a veil?"
Thereupon, {There is no blame upon them} was revealed, meaning: there is no sin upon them if they do not veil themselves from these [specific relatives].
The paternal uncle and maternal uncle were not mentioned because they hold the same status as parents. Indeed, the paternal uncle has been referred to as a "father." God Almighty said: {And the God of your fathers, Abraham, Ishmael, and Isaac} (Al-Baqarah: 133), and Ishmael was the uncle of Jacob.
It is also said: It was disliked to abandon veiling from them [the uncles] because they might describe the woman to their own sons, and their sons are not maḥram (unmarriageable kin).
Then, the discourse shifts from the third person to the second person. In this shift, there is an indication of the virtue of strictness. Thus, it is said: {And fear God} regarding what you have been commanded concerning the veil, and the revelation that was sent down regarding concealment. Observe it, and observe what has been exempted from it as much as you are able. Guard its limits, follow the path of piety in maintaining them, and let your conduct regarding the veil be better than it was when you were unveiled, so that your inner state may excel your outer state.
{Indeed, God is ever, over all things}—of the secret and the manifest, the outward veil and the inward—{a Witness}, whose knowledge of all states does not vary.
{Indeed, God and His angels send blessings upon the Prophet. O you who have believed, ask [God to send] blessings upon him and ask [God to grant him] peace.}