Is it permissible for the wealthy to receive donations and wakaf?
Alhamdulillah, praise and gratitude to Allah SWT for His countless blessings for us all. Praise and salutations to our beloved Prophet Muhammad PBUH, his family, companions and all those who follow his footsteps until the Last Day.
Sadaqah (donation) means a gift given to others for the sake of seeking rewards from Allah SWT. 
While Ibn Manzur defined donation as whatever you give for the sake of Allah to the poor and needy, who are in need. 
There is a hadith narrated from Abu Hurairah RA, where the Messenger PBUH said:
إِذَا مَاتَ الإِنْسَانُ انْقَطَعَ عَنْهُ عَمَلُهُ إِلاَّ مِنْ ثَلاَثَةٍ إِلاَّ مِنْ صَدَقَةٍ جَارِيَةٍ أَوْ عِلْمٍ يُنْتَفَعُ بِهِ أَوْ وَلَدٍ صَالِحٍ يَدْعُو لَهُ
“When a son of Adam (i.e. any human being) dies his deeds are discontinued, with three exceptions: Sadaqah, whose benefit is continuous; or knowledge from which benefit continues to be reaped, or a righteous child who supplicates for him.” 
Imam al-Nawawi said, the meaning of sadaqah in the hadith is wakaf. This hadith is evidence of the validity of wakaf deed and its great rewards. 
Wakaf according to 4th Edition of Kamus Dewan is something given for public use or something dedicated to the needs related to the religion of Islam. For example, wakaf land reserved for religious purposes such as to be made as a graveyard, build a mosque and others.
Wakaf originates from the Arabic word waqf which is a derivative (masdar) from the verb waqafa. It has various meanings following the purpose and usage of the sentence itself. Lexically, waqf means stop (السكن), prevent (المنع) and impede (الحبس). (See Lisan al-‘Arab, 9/359) In terms of the usage of the terminology, wakaf is impeding something from being owned and that its benefits are to be donated. Hence, the ownership of the asset changed to the ownership of Allah SWT. 
Sayyid Sabiq stated wakaf is impeding something from being owned by the person that wakaf the asset and donating its benefits in Allah SWT’s road. 
Dr Wahbah al-Zuhayli said, wakaf is halting a permanent immovable asset for charitable purposes and it is handed over to certain chosen parties with the hope to get closer to Allah SWT. 
Regarding riches or wealth, Imam Hassan al-Banna in stating the first principle of Islam’s perfection is that its ummah has to have a determination in seeking sustenance or striving to attain wealth from the sustenance of Allah SWT. 
Basically, the wealthy are those who are ineligible to receive zakat due to the riches they own or their income or their capability to provide sustenance to others. 
However, this is different from the concept of zakat, syarak permits giving wakaf to the wealthy. 
The reason is that the concept of zakat is different from the distribution of zakat set in al-Quran. This means although the wealthy aren’t permitted to receive zakat, however, they have a right to receive wakaf. 
We present a story of a man who donated as stated in a long hadith narrated by Abu Hurairah RA, where the Messenger PBUH said:
قَالَ رَجُلٌ لأَتَصَدَّقَنَّ بِصَدَقَةٍ فَخَرَجَ بِصَدَقَتِهِ فَوَضَعَهَا فِي يَدِ سَارِقٍ فَأَصْبَحُوا يَتَحَدَّثُونَ تُصُدِّقَ عَلَى سَارِقٍ. فَقَالَ اللَّهُمَّ لَكَ الْحَمْدُ لأَتَصَدَّقَنَّ بِصَدَقَةٍ فَخَرَجَ بِصَدَقَتِهِ فَوَضَعَهَا فِي يَدَىْ زَانِيَةٍ، فَأَصْبَحُوا يَتَحَدَّثُونَ تُصُدِّقَ اللَّيْلَةَ عَلَى زَانِيَةٍ فَقَالَ اللَّهُمَّ لَكَ الْحَمْدُ عَلَى زَانِيَةٍ، لأَتَصَدَّقَنَّ بِصَدَقَةٍ فَخَرَجَ بِصَدَقَتِهِ فَوَضَعَهَا فِي يَدَىْ غَنِيٍّ فَأَصْبَحُوا يَتَحَدَّثُونَ تُصُدِّقَ عَلَى غَنِيٍّ فَقَالَ اللَّهُمَّ لَكَ الْحَمْدُ، عَلَى سَارِقٍ وَعَلَى زَانِيَةٍ وَعَلَى غَنِيٍّ فَأُتِيَ فَقِيلَ لَهُ أَمَّا صَدَقَتُكَ عَلَى سَارِقٍ فَلَعَلَّهُ أَنْ يَسْتَعِفَّ عَنْ سَرِقَتِهِ، وَأَمَّا الزَّانِيَةُ فَلَعَلَّهَا أَنْ تَسْتَعِفَّ عَنْ زِنَاهَا، وَأَمَّا الْغَنِيُّ فَلَعَلَّهُ يَعْتَبِرُ فَيُنْفِقُ مِمَّا أَعْطَاهُ اللَّهُ
“A man (from amongst the people before you) said: ‘Indeed! I will give in charity.’ So he took his Sadaqah out and placed it in a thief’s hand. In the morning the people were talking (about this incident) and saying: ‘Sadaqah was given to a thief last night.’ The man said: ‘O Allah! Praise be to You. I have given Sadaqah to a thief. Indeed, I will give in charity!’ So he took his Sadaqah out and he placed it in a prostitute’s hand. In the morning the people were talking (about this incident) and saying: ‘Sadaqah was given to a prostitute last night.’ On hearing this, the man said: ‘Praise be to You, O Allah! I gave Sadaqah to a prostitute. Indeed, I will give in charity!’ So he took his Sadaqah out and placed it in a rich man’s hand. In the morning the people were talking (about this incident) and saying: ‘Sadaqah was given to a rich man last night.’ The man said: ‘O Allah! Praise be to You (for helping me) give charity to a thief, a prostitute and a rich man.’ Then he had a dream in which he was told that his Sadaqah to the thief might result in his refraining from his theft, his Sadaqah to the prostitute might help her abstain from her immorality, and his Sadaqah to the rich man might help him pay heed and spend from what Allah had bestowed upon him.” 
We see that the wealthy don’t have a right to receive zakat, however, syarak permits giving sadaqah (donation) and wakaf to the wealthy. The reason is the wealthy are included as those who are rightful to own property and it is permissible for them to receive a donation. Thus, the ruling of giving wakaf to the wealthy is valid and permitted by syarak.
Hopefully, this explanation will give us a better understanding of Islam. Amin.