Buhaysah narrated from her father: He went to the Prophet Muhammad (peace be upon him), sought permission to enter, then put his mouth inside the curtain and began to embrace (kiss) him. Then he asked: What is it that it is not permissible to withhold? He said: "Salt and water." Then he asked: What is it that it is not permissible to withhold? He said: "The more good you do, the better." Then he asked: What is it that it is not permissible to withhold? He said: "The more good you do, the better," and he sufficed with only salt and water. Imam Darimi (may Allah have mercy on him) was asked: Do you also say the same? He nodded his head in affirmation.
Hadith Takhrijاس حدیث کی سند جید ہے۔ دیکھئے: [أبوداؤد 1669، 3476] ، [أبويعلی 7177] ، [ابن حزم فى المحلی 54/9]
Brief Explanation
(Commentary on Hadith 2648)
That is, it is not permissible in any way to prevent the taking of water and salt, and whatever thing is spent for reward and recompense, the more it is spent, the greater the reward will be.
From this hadith, it is established that selling or preventing access to salt and water is prohibited; the details have already been mentioned above.