Allah (SWT) has created water for living things to benefit from. People require water for almost everything; for agriculture, construction, transportation, and many other benefits. But scientifically speaking, there are several kinds of water. Similar to the scientific classification, it is also believed, by Muslims, that the Zamzam water is the most important and purified. They crave this mysterious liquid and love to drink it whenever they can. And for those who managed to go to the Hajj, they return home carrying it for thousands of miles as a prized possession and to give as special gift to their friends and families
With that being said, lets have a look at the hadith perspective on the importance of Zamzam.
On the authority of Muhammad ibn Abi Bakr, peace and blessings of Allah be upon him, reported: I was sitting with Abdullah ibn Abbas when a man came and he said, “From where did you come?” The man said, “From the Zamzam well.” Ibn Abbas said, “Did you drink from it as you should?” The man said, “How is that?” Ibn Abbas said, “When you drink from it, then face the direction of prayer and remember the name of Allah and drink three times and drink your fill. When you finish, then praise Allah the Exalted. I heard the Messenger of Allah, peace and blessings be upon him, say, “Verily, the sign between us and the hypocrites is that they do not drink Zamzam water.”
عَنْ مُحَمَّدِ بْنِ عَبْدِ الرَّحْمَنِ بْنِ أَبِي بَكْرٍ قَالَ كُنْتُ عِنْدَ ابْنِ عَبَّاسٍ جَالِسًا فَجَاءَهُ رَجُلٌ فَقَالَ مِنْ أَيْنَ جِئْتَ قَالَ مِنْ زَمْزَمَ قَالَ فَشَرِبْتَ مِنْهَا كَمَا يَنْبَغِي قَالَ وَكَيْفَ قَالَ إِذَا شَرِبْتَ مِنْهَا فَاسْتَقْبِلْ الْقِبْلَةَ وَاذْكُرْ اسْمَ اللَّهِ وَتَنَفَّسْ ثَلَاثًا وَتَضَلَّعْ مِنْهَا فَإِذَا فَرَغْتَ فَاحْمَدْ اللَّهَ عَزَّ وَجَلَّ فَإِنَّ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ قَالَ إِنَّ آيَةَ مَا بَيْنَنَا وَبَيْنَ الْمُنَافِقِينَ إِنَّهُمْ لَا يَتَضَلَّعُونَ مِنْ زَمْزَمَ
Source: Sunan Ibn Majah 3061
Grade: Sahih (authentic) according to As-Suyuti