Assalamualaikum w.b.t. I have non-Muslim neighbours who are very close to me. Recently, I just returned from umrah and wanted to give Zamzam water to my neighbours including the non-Muslims. My question is, is it permissible for me to give it to non-Muslims? Thank you.
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.
Zamzam water is the best all of water on this earth. Zamzam is the name of a well in the Masjid Haram Mosque in Mecca. The well first appeared during the time of the Prophet Ismail bin Abraham AS, when Allah SWT prepared water from this well for him when he was hungry and thirsty with his mother because they have finished the water that they brought to Mecca which was barren at the time.
Among the special characteristics of Zamzam water is that it is blessed water and is able to satiate and fill whoever drinks it as well as a cure for all diseases. We have discussed this matter in detail in our previous articles:
- 369 The Blessings of ZamZam Water Isn’t Bound to the Holy Land. 
- 374 The Permissibility of Transporting Zamzam Water Out of Mecca. 
- 436 Bathing with Zamzam Water. 
Giving Zamzam water to non-Muslims
Coming back to the above question, we did not find any prohibition or restriction against giving Zamzam water to non-Muslims, whether it is stated in history or in the hadiths of the Prophet PBUH. Thus, its original ruling remains, that is it is permissible. This follows the Islamic legal maxim that states:
الْأَصْلُ فِي الْأَشْيَاءِ الْإِبَاحَةُ حَتَّى يَدُلُّ الدَّلِيلُ عَلَى التَّحْرِيمِ
“The original ruling for a certain matter is its permissibility until there is evidence presented that shows its prohibition.” 
Furthermore, during the opening of the city of Mecca, there is nothing in the speech of Rasullullah PBUH that restricts the musyrik – non-Muslims- from drinking Zamzam water, even when they are residing in Mecca. Moreover, Syeikh Mustafa al-‘Adawi when asked regarding the ruling of non-Muslims drinking Zamzam water, he answered saying that there isn’t any restriction on this matter.  Hence, if they are permitted to drink it, then the same ruling applies in this matter – that is giving Zamzam water to them.
Not only that, it may be possible that our small act of kindness will soften their hearts to embrace Islam and change their perspective toward Islam in a positive light. Furthermore, Islam never prohibits its followers from doing good to non-Muslims, rather, it commanded its followers to always do good and act fairly and with justice to everyone, regardless of their religion – non-Muslims. Allah SWT states:
لَّا يَنْهَاكُمُ اللَّـهُ عَنِ الَّذِينَ لَمْ يُقَاتِلُوكُمْ فِي الدِّينِ وَلَمْ يُخْرِجُوكُم مِّن دِيَارِكُمْ أَن تَبَرُّوهُمْ وَتُقْسِطُوا إِلَيْهِمْ ۚ إِنَّ اللَّـهَ يُحِبُّ الْمُقْسِطِينَ
“Allah does not forbid you from those who do not fight you because of religion and do not expel you from your homes – from being righteous toward them and acting justly toward them. Indeed, Allah loves those who act justly.” 
Thus, in our opinion, it is permissible to give Zamzam water to non-Muslims, for there isn’t any prohibition or restriction in this matter. Moreover, the consequence is commendable, especially in showcasing the good and positive character of a Muslim. Hopefully, some of the good acts we do can soften their hearts to look at the goodness of the religion of Islam and subsequently encourage them to embrace this honoured religion.
May Allah SWT grant us all a clear understanding in this religion. Amin.
 See al-Asybah wa al-Naza’ir oleh al-Suyuti, pg. 60.
 Surah al-Mumtahinah: 8