Tafsir of Al-Isra 17:26-27

{And give the relative his right} He enjoined [kindness to] relatives other than the parents, following the injunction regarding them, and that they be given their right. Their right, if they are mahram (unmarriageable kin) like parents and children, and they are poor and unable to earn, while the man is wealthy, is that he must provide for them according to Abu Hanifa. Al-Shafi‘i, however, does not see an obligation of maintenance except for children and parents only.

If they are wealthy, or not mahram—such as cousins—their right is to maintain ties with them through affection, visitation, good companionship, harmony in times of ease and hardship, mutual support, and the like.

{And the needy and the wayfarer} Meaning: Give these people their right from Zakat. This is evidence that what is intended by the "right" given to relatives is providing for them with wealth. It has also been said: He intended by "the relative" the relatives of the Messenger of Allah (ﷺ).

{And do not spend wastefully} Tabdhir (wastefulness) is the squandering of wealth in ways that are not appropriate, and spending it in a manner of extravagance. The people of the Jahiliyyah used to slaughter their camels, gamble with them, and squander their wealth for the sake of pride and reputation, mentioning this in their poetry. So, Allah commanded spending in its proper avenues, which draw one closer to Him.

• From ‘Abdullah: It is spending wealth in other than its rightful place.
• From Mujahid: If one were to spend a mudd (a measure) in falsehood, it would be tabdhir.
• Some people spent a great deal on charity, and a companion said to him, "There is no good in extravagance." He replied, "There is no extravagance in good."
• From ‘Abdullah ibn ‘Amr: The Messenger of Allah (ﷺ) passed by Sa‘d while he was performing ablution and said, "What is this extravagance, O Sa‘d?" He asked, "Is there extravagance in ablution?" He replied, "Yes, even if you are by a flowing river."

{Are brothers of the devils} They are their peers in evil, which is the ultimate condemnation, for there is no evil greater than that of the Devil. Or, they are their brothers and friends because they obey them in the extravagance they command. Or, they are their companions in the Fire, by way of threat.

{And the Devil was ever ungrateful to his Lord} So he should not be obeyed, for he only calls to the likes of his own deeds. Al-Hasan read it as: Ikhwan al-Shaytan (Brothers of the Devil).

{And if you turn away from them, seeking mercy from your Lord which you hope for, then speak to them a gentle word}