Al-Mu'jam al-Awsat 6592 — she said: O Messenger of Allah! What

It is narrated from the Mother of the Believers, Sayyidah Aishah (may Allah be pleased with her), that she said: "O Messenger of Allah! What is the thing which it is not lawful to withhold (from one in need)?" He (peace and blessings be upon him) said: "Water, salt and fire." She said: "We understand (the need for) water, but what about salt and fire?" He (peace and blessings be upon him) said: "Whoever gives salt, it is as if he has given in charity all the (food) that this salt has made tasty; whoever gives fire, it is as if he has given in charity all that this fire has cooked; whoever gives a Muslim a drink of water in a place where water is commonly found, it is as if he has freed a slave; and whoever gives a Muslim a drink of water in a place where water is not available, it is as if he has given him life."
Zuhayr bin Marzuq (may Allah have mercy on him) did not narrate any musnad report other than this, and Ali bin Ghurab (may Allah have mercy on him) is alone in narrating it.