Treatment from Rain-water (Aab e Neeysaan)

الْحَسَنُ بْنُ الْفَضْلِ الطَّبْرِسِيُّ فِي مَكَارِمِ الْأَخْلَاقِ عَنْ رَسُولِ اللَّهِ ص أَنَّهُ قَالَ: عَلَّمَنِي جَبْرَئِيلُ‏ دَوَاءً لَا أَحْتَاجُ‏ مَعَهُ‏ إِلَى‏ دَوَاءٍ قِيلَ‏ يَا رَسُولَ اللَّهِ وَ مَا ذَلِكَ الدَّوَاءُ قَالَ يُؤْخَذُ مَاءُ الْمَطَرِ قَبْلَ أَنْ يَنْزِلَ إِلَى الْأَرْضِ ثُمَّ يَجْعَلُ فِي إِنَاءٍ نَظِيفٍ وَ يَقْرَأُ عَلَيْهِ الْحَمْدَ إِلَى آخِرِهَا سَبْعِينَ مَرَّةً وَ قُلْ هُوَ اللَّهُ أَحَدٌ وَ الْمُعَوِّذَتَيْنِ سَبْعِينَ مَرَّةً ثُمَّ يَشْرَبُ مِنْهُ قَدَحاً بِالْغَدَاةِ وَ قَدَحاً بِالْعَشِيِّ فَوَ الَّذِي بَعَثَنِي بِالْحَقِّ لَيَنْزِعَنَّ اللَّهُ بِذَلِكَ الدَّاءَ مِنْ بَدَنِهِ وَ عِظَامِهِ وَ مِخَخَتِهِ‏ وَ عُرُوقِهِ.

Al-Hassan ibn al-Fadl Al-Tabrisi in Makarim al-Akhlaq on the authority of the Rasool Allah-saww that he said: Teach me:

(So, Rasool Allah-saww said:) Gabriel-as taught me a medicine with which I do not need (any other) medicine. It was said, O Rasool Allah-saww, and what is that medicine? He‑saww said, “The rain water is taken before it falls to the ground, then put it in a clean vessel, and recite Al-Hamd to it until the end (70) seventy times, and 70 time Qul ho wallah, and 70 times Mouzateen (Qul Ouzo Bay Rab Falaq and Qul Ouzo Bay Rabay Naas), then he drinks a cup of it in the morning and a cup of it in the evening  (illness will be extracted) from his body, his bones, his brain, and his veins.[1].

[1] وسائل الشيعة، ج‏25، ص: 265, 31873- 1-, H. 21